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Daily and Seasonal Rhythms

Herbert A. Underwood, Gary T. Wassmer, Terry L. Page

10.1002/cphy.cp130224

Source: Supplement 30: Handbook of Physiology, Comparative Physiology

Originally published: 1997

Published online: January 2011

Full Article on Wiley Online Library



Abstract

The sections in this article are:

1 Daily Rhythms
1.1 Models and Mechanisms
2 Circadian Pacemaking Systems in Invertebrates
2.1 Pacemakers in the Arthropod Brain
2.2 Circadian Pacemakers Outside the Nervous System in Insects
2.3 Pacemakers in the Gastropod Retina
2.4 Multioscillator Organization
2.5 Identification of Output Pathways
3 Circadian Pacemaking Systems in Vertebrates
3.1 The Mammalian SCN
3.2 Other Circadian Oscillators in Mammals
3.3 Hypothalamic Regulation of Circadian Function in Nonmammalian Vertebrates
3.4 The Pineal Organ
3.5 Eyes as Clocks
4 Photoreceptor Localization and Mechanisms of Entrainment in Invertebrates
4.1 Photoreceptive Input: Invertebrates
4.2 Mechanisms of Regulation of Pacemaker Phase
5 Photoreceptor Localization and Mechanisms of Entrainment in Vertebrates
5.1 Identification of Photoreceptors
5.2 Mechanisms of Regulation of Pacemaker Phase
6 Seasonality in Invertebrates
6.1 Modes of Seasonality
6.2 Timing of Seasonal Cycles
6.3 Photoperiodic Time Measurement
6.4 Mechanisms of Photoperiodic Time Measurement
6.5 The Photoperiodic Timer
6.6 The Photoperiodic Counter
6.7 Anatomical Location of Timers and Counters
6.8 Photoreceptors
6.9 Circannual Rhythms
7 Seasonality in Vertebrates
7.1 Photoperiodic Time Measurement: Models and Experimental Validation
8 Physiological Mechanisms
8.1 The Pineal and Melatonin: Mammals
8.2 Mechanisms of Pineal Action
8.3 The Pineal and Melatonin: Nonmammalian Vertebrates
8.4 Photoreceptive Inputs: Mammalian
8.5 Photoreceptive Inputs: Nonmammalian
8.6 Maternal–Fetal Transfer of Photoperiodic Information
9 Circannual Rhythms
9.1 Physiological Mechanisms
10 Concluding Comments
Figure 1. Figure 1.

Effects on locomotor activity of optic lobe transplantation between groups of cockroaches raised in LD 11:11 or LD 13:13. A: Locomotor activity records showing restoration of rhythmicity after transplantation (exchange). The record begins with the animals free‐running in DD. After 4 weeks, optic lobes were exchanged, and after several weeks of low activity, rhythmicity returned in both cases. B: Plots of free‐running period of the activity rhythm after transplantation vs. period of the donor animal before surgery. Diagonal line shows values expected if pre‐ and postoperative periods were identical; CST, central standard time.

data from Page [706,708]
Figure 2. Figure 2.

Data from animals treated with localized low‐temperature pulses. Solid circles, time of activity onset for each day; open circles, projected phases of rhythms before and after pulse; lines are linear regressions; PST, Pacific standard time. Pulses were 6 h in duration and began at activity onset (CT12). In A, the intact optic lobe of an animal with one sectioned optic tract was cooled to 7°C while the isolated lobe was maintained at 25°C, and in B, the isolated lobe was cooled. Cooling the intact lobe caused a large phase‐delay, while cooling the isolated lobe had no effect. C and D illustrate the effects of a low‐temperature pulse to one lobe on the rhythm driven by the opposite lobe. C : The optic tract of the treated lobe was cut 4 days after pulse, and the subsequent rhythm, driven by the untreated lobe, was phase‐delayed by several hours. D: The optic tract of the treated lobe was sectioned 0.5 h after pulse, preventing the phase shift of the rhythm. CP, cold pulse; OTX, optic tract section.

from Page [709]
Figure 3. Figure 3.

Time of eclosion of Hyalophora cecropia and Antheraea pernyi moths in LD 17:7, showing effects of brain removal, transplantation of brain to abdomen, and interchange of brains between the two species. After brain exchange, the host emerges at the eclosion time characteristic of the donor species.

from Truman [1002]
Figure 4. Figure 4.

Rhythm of sperm movement in intact gypsy moths, Lymantria dispar, (A) or in testis–upper vas deferens (UVD)–seminal vesicle complexes isolated in vitro at times indicated by arrows (B, C). In A and B, preparations were exposed to LD 16:8 (illustrated by bars at the bottom of each record), while in C, the complex was released in DD.

from Giebultowicz et al. [354]
Figure 5. Figure 5.

Frequency of spontaneous compound action potentials (CAPs) recorded in DD from optic nerves of Bulla gouldiana. The two eyes and attached central ganglia were isolated in vitro in artificial seawater. On the third day of the record, the two eyes were uncoupled by severing the cerebral and pedal connectives (CX). Uncoupling the two ocular pacemakers had little or no effect on the free‐running period, amplitude, or persistence of the rhythm. FASW, filtered artificial sewater.

from Page and Nalovic [723]
Figure 6. Figure 6.

Locomotor activity record from the cricket Teleogryllus commodus. Prior to the beginning of the experiment, one optic nerve was cut, isolating one optic lobe pacemaker from input from its compound eye (see schematic in inset). After 14 days, the animal was placed in LL. Treatment lengthens the period of the optic lobe pacemaker still attached to its eye, desynchronizing its component of activity. On day 40, that optic lobe is removed (LOBX), eliminating the long period component.

from Wiedenmann [1136]
Figure 7. Figure 7.

Rhythms in electroretinogram (ERG) amplitude and efferent impulse activity in optic nerve of the horseshoe crab Limulus polyphemus. On the left is a schematic of the experimental arrangement. The ERG in response to a brief light pulse delivered via the light pipe was recorded from the left eye, while an electrode placed on the right optic nerve recorded efferent impulse activity. ERG amplitude (top) and efferent impulse frequency (bottom) show strongly correlated circadian rhythms.

from Barlow [41]
Figure 8. Figure 8.

In vitro rhythmicity in SCN explants. Upper panel: time histogram of firing frequency in a single SCN neuron. Lower panel: circadian oscillation of vasopressin release. (Upper figure; lower figure.)

adapted from Bos and Mirmiran [111] adapted from Murakami et al. [674]
Figure 9. Figure 9.

Transplantation of SCN tissue restores rhythmicity in SCN‐lesioned hosts, and the restored rhythm bears the period of the donor. Left panel shows the effect of transplanting SCN tissues from a 20 h period mutant donor into an SCN‐lesioned wild‐type host. Right panel shows the effect of transplanting SCN tissue from a wild‐type donor (period = 24 h) into an SCN‐lesioned heterozygote mutant host. Data in the left panel have been plotted at 20 h intervals to help visualize rhythmicity. SCNX, suprachiasmatic nucleus lesion; T, transplantation.

from Ralph et al. [767]
Figure 10. Figure 10.

Metabolic pathway describing pineal indoleamine derivatives of tryptophan. Enzymes: (1) tryptophan hydroxylase, (2) aromatic L‐amino acid decarboxylase, (3) N‐acetyltransferase, (4) monoamine oxidase, (5) aldehyde dehydrogenase, (6) hydroxyindole‐O‐methyltransferase.
Figure 11. Figure 11.

Schema of activity patterns showing effects of pinealectomy in three classes of vertebrate. Top panel: Columba livia (pigeon), Passer domesticus (house sparrow), Sturnus vulgaris (starling). Middle panel: Sceloporus olivaceus (Texas spiny lizard), Anolis carolinensis (green anole), Sceloporus occidentalis (Western fence lizard). Lower panel: Catostomus commersoni (white sucker), Heteropneustes fossilis (catfish), Lota lota (burbot). P, pinealectomized.
Figure 12. Figure 12.

Restoration of rhythmicity by transplantation of a pineal into the eye of a pinealectomized house sparrow. Donors' light cycles are diagrammed at the top of their respective records. Pinealectomized recipients were in DD.

from Zimmerman and Menaker [1165]
Figure 13. Figure 13.

In vitro patterns of melatonin secretion from individual pineal glands of the chicken Gallus domesticus, the green anole Anolis carolinensis, the desert iguana Dipsosaurus dorsalis, the pike Esox lucius, and the trout Salmo gairdneri. Left panels show melatonin patterns expressed under 24 h LD cycles and right panels show patterns expressed in DD.

adapted from Takahashi et al. [967] adapted from Menaker and Wisner [632] adapted from Janik and Menaker [496] adapted from Falcon et al. [290] adapted from Gern and Greenhouse [347]
Figure 14. Figure 14.

Melatonin infusion cycles with a period of 24.4 h entrain the feeding rhythm of a pinealectomized pigeon. The bird was held in DD and given 10 h of continuous melatonin (M) every 24.4 h.

from Chabot [172])
Figure 15. Figure 15.

Both light and temperature affect the pineal melatonin rhythm of reptiles. A: Annual changes in the daily rhythm of pineal melatonin content in the tortoise Testudo hermanni held under natural conditions of photoperiod and temperature (adapted from Vivien‐Roels et al. [1094]). B : Effects of amplitude reduction of a 24 h temprature cycle on the phase of the pineal melatonin rhythm of green anoles (Anolis carolinensis). Anoles were exposed to a temperature cycle in which the cool phase occurred during either day (left panel) or night (right panels). Pineal melatonin rhythm is entrained by the temperature cycle if the cycle is of high amplitude (32°/20°) but by the light cycle if the cycle is of low amplitude (32°/30°).

from Underwood [1036]
Figure 16. Figure 16.

Circadian rhythms of melatonin release from individual eyecups of the African clawed frog Xenopus laevis can be reset by light. Control eyecups (dashed lines) were held in DD and experimental eyecups (solid lines) were exposed to a 6 h pulse of white light during the times indicated at the top of each figure. Light pulses presented during the subjective day were without effect, pulses during the early part of the subjective night caused a delay in the phase of the rhythm, and pulses presented during the late subjective night caused an advance in the phase of the rhythm.

Adapted from Cahill and Besharse [145]
Figure 17. Figure 17.

Blinding by enucleation (EX) disrupts the circadian body temperature rhythm of Japanese quail. Actogram record (left panel) shows the body temperature rhythm of a blinded quail. The bird was rhythmic when held under LD 12:12 (diagrammed at the top of the figure) but became arrhythmic after being placed into DD. Right panels show results of F‐periodogram analysis of body temperature during LD (top) or DD (bottom): the bird was rhythmic under LD but arrhythmic under DD. By contrast, unoperated birds remained rhythmic in DD 1038.
Figure 18. Figure 18.

Extraretinal photoreceptors mediate entrainment in nonmammalian vertebrates. A: Entrainment of perch‐hopping activity of a blinded house sparrow to an LD 12:12 light cycle. At the point marked 1, the phase of the LD cycle was shifted, and at the point marked 2, the bird was exposed to DD (from Menaker [626]). B: Entertainment of a blinded Texas spiny lizard to an LD 12:12 light cycle.

from Underwood [1026]
Figure 19. Figure 19.

Models of mammalian (A) and nonmammalian (B) circadian systems. LGN, lateral geniculate nucleus; SCN, suprachiasmatic nucleus; RH, retinohypothalamic; ERR, extraretinal receptor.
Figure 20. Figure 20.

Activity feedback affects the circadian pacemaker of mammals. A: Representative activity records from hamsters free‐running in LL and given pulses of induced wheel‐running (between triangles) (from Reebs et al. [777]. B: Phase response curves for 30 min social interaction (top panel), cage changing (middle panel), and 2 h of novelty‐induced wheel‐running in hamsters.

adapted from Mrosovsky et al. [670]
Figure 21. Figure 21.

Daily feeding entrains a circadian oscillator in rats. The rat was fed for 2 h (marked with arrows) under LD 14:10, then placed into DD and presented with periods of feeding ad libitum (F) or food deprivation (N). The food‐associated rhythm persists in DD and can be discerned during periods of food deprivation but not during a libitum feeding.

adapted from Clarke and Coleman [186]
Figure 22. Figure 22.

Sample photoperiodic response curves: (A) pupal diapause of Yponomeuta vigintipunctatus 1084; (B) egg diapause of Aedes atropalpus 55; (C) adult diapause of Stenocranus minutus 672; (D) larval diapause of Carposina niponensis 1000.
Figure 23. Figure 23.

Effect of latitude (A) and temperature (B) on induction of larval diapause of Acronycta rumicis. The latitude from which the strain was collected and the temperature at which the experiment was conducted are given next to the appropriate photoperiodic response curve 212.
Figure 24. Figure 24.

Bünning's model for the photoperiodic clock. The photoperiodic time‐measuring system oscillates between periods of sensitivity (filled in part of the curve) and insensitivity to light. Upper panel depicts the rhythm free‐running under constant conditions and the two lower panels show the effects of a short day (middle panel) and a long day (bottom panel). If the days are long enough, they extend into the sensitive phase of the rhythm and a photoperiodic response is initiated.

adapted from Bünning [143]
Figure 25. Figure 25.

Positive and negative responses to the Nanda‐Hamner protocol. Various scotophases are combined with an 8 h photophase. Experimental LD cycles shown on bottom of figure. Positive response (dotted line) for diapause induction of the red spider mite Tetranychus urticae 1087. Note the periodic maxima approximately 24 h apart. Negative response (solid line) for virginopara production of Megoura viciae 565.
Figure 26. Figure 26.

Positive and negative responses to the night‐break protocol. A short photophase (8 or 12 h) is combined with a 64 h scotophase and 1 h light break during the extended night. Experimental LD cycles shown on bottom of figure. Positive response (dotted line) for Tetranychus urticae 1080. Note the periodic maxima approximately 24 h apart. Negative response (solid line) for Megoura viciae 567.
Figure 27. Figure 27.

Effects of transferring developing larvae of two species from long (L) to short (S) photoperiods, or short to long, at different stages of development. Numbers on abscissa refer to the instar during which the transfer was made. Note that the sensitive period appears to comprise the entire period of larval development and that the diapause‐averting effects of long days are greater than the diapause‐promoting effects of short days. Data for Antberaea pernyi from Tanaka 979 and those for Ostrinia nubilalis from Beck 58.
Figure 28. Figure 28.

Effect of temperature on induction of pupal diapause in Sarcophaga argyrostoma at LD 10:14, showing interaction between the sensitive period and the required day number. Polygons show the proportion of each batch of larvae forming puparia each day; shaded portions of polygons represent larvae which became diapausing pupae. Note that the sensitive period and the required day number have different temperature coefficients. At high temperatures (26° and 24°C), the sensitive period is shorter than the required day number and few, if any, of the pupae enter diapause, whereas the opposite is true at lower temperatures (14° and 16°C). Inset: Effect of temperature on proportion of diapause pupae at LD 10:14. Figure and legend from Saunders 867.
Figure 29. Figure 29.

Gonadal response and activity patterns of Syrian hamsters exposed to resonance and T‐experiment lighting protocols. A: Upper panel shows wheel‐running patterns of hamsters entrained to four different resonance light cycles; lower panel, testicular response to these light cycles. Cycles in which light impinged on the animals' subjective night were inductive (LD 6:30, LD 6:54), whereas cycles in which light impinged only on the subjective day (LD 6:18, LD 6:42) were not (from Elliott et al. [277]). B: Upper panel shows wheel‐running activity of hamsters entrained to three different light cycles using 1 h light pulses. Line connects midpoints of 1 h light pulses. Lower panel shows testicular response to various T‐cycles (1 h light pulses). Photoperiodic stimulation of testicular growth is dependent on the position of the 1 h light pulse relative to the circadian system. Testicular growth occurs only if the light pulse entrains the circadian system such that light falls during subjective night (that is, the sensitive phase of Bünning's rhythm).

from Elliott [273]
Figure 30. Figure 30.

Action spectrum for the extraretinal photoreceptors mediating the photoperiodic response in Japanese quail; LH, luteinizing hormone.

adapted from Foster et al. [321]
Figure 31. Figure 31.

Maternal transfer of photoperiodic information to pups in utero. Figures show paired testes weights of Djungarian hamsters gestated and raised on the indicated photoperiods. The postnatal photoperiod is stimulatory or not depending on the photoperiod experienced by the mother during pregnancy.

adapted from Stetson et al. [944]
Figure 32. Figure 32.

Effects of pinealectomy and melatonin infusion on the annual reproductive cycle of sheep. Timing of high luteinizing hormone stages (horizontal solid bars) becomes uncoupled from the environment after pinealectomy (left panel), but short‐day (SD Mel, batched vertical box) and long‐day (LD Mel, open box) melatonin infusions entrain the reproductive cycle of pinealectomized ewes

adapted from Woodfill et al. [1149]


Figure 1.

Effects on locomotor activity of optic lobe transplantation between groups of cockroaches raised in LD 11:11 or LD 13:13. A: Locomotor activity records showing restoration of rhythmicity after transplantation (exchange). The record begins with the animals free‐running in DD. After 4 weeks, optic lobes were exchanged, and after several weeks of low activity, rhythmicity returned in both cases. B: Plots of free‐running period of the activity rhythm after transplantation vs. period of the donor animal before surgery. Diagonal line shows values expected if pre‐ and postoperative periods were identical; CST, central standard time.

data from Page [706,708]


Figure 2.

Data from animals treated with localized low‐temperature pulses. Solid circles, time of activity onset for each day; open circles, projected phases of rhythms before and after pulse; lines are linear regressions; PST, Pacific standard time. Pulses were 6 h in duration and began at activity onset (CT12). In A, the intact optic lobe of an animal with one sectioned optic tract was cooled to 7°C while the isolated lobe was maintained at 25°C, and in B, the isolated lobe was cooled. Cooling the intact lobe caused a large phase‐delay, while cooling the isolated lobe had no effect. C and D illustrate the effects of a low‐temperature pulse to one lobe on the rhythm driven by the opposite lobe. C : The optic tract of the treated lobe was cut 4 days after pulse, and the subsequent rhythm, driven by the untreated lobe, was phase‐delayed by several hours. D: The optic tract of the treated lobe was sectioned 0.5 h after pulse, preventing the phase shift of the rhythm. CP, cold pulse; OTX, optic tract section.

from Page [709]


Figure 3.

Time of eclosion of Hyalophora cecropia and Antheraea pernyi moths in LD 17:7, showing effects of brain removal, transplantation of brain to abdomen, and interchange of brains between the two species. After brain exchange, the host emerges at the eclosion time characteristic of the donor species.

from Truman [1002]


Figure 4.

Rhythm of sperm movement in intact gypsy moths, Lymantria dispar, (A) or in testis–upper vas deferens (UVD)–seminal vesicle complexes isolated in vitro at times indicated by arrows (B, C). In A and B, preparations were exposed to LD 16:8 (illustrated by bars at the bottom of each record), while in C, the complex was released in DD.

from Giebultowicz et al. [354]


Figure 5.

Frequency of spontaneous compound action potentials (CAPs) recorded in DD from optic nerves of Bulla gouldiana. The two eyes and attached central ganglia were isolated in vitro in artificial seawater. On the third day of the record, the two eyes were uncoupled by severing the cerebral and pedal connectives (CX). Uncoupling the two ocular pacemakers had little or no effect on the free‐running period, amplitude, or persistence of the rhythm. FASW, filtered artificial sewater.

from Page and Nalovic [723]


Figure 6.

Locomotor activity record from the cricket Teleogryllus commodus. Prior to the beginning of the experiment, one optic nerve was cut, isolating one optic lobe pacemaker from input from its compound eye (see schematic in inset). After 14 days, the animal was placed in LL. Treatment lengthens the period of the optic lobe pacemaker still attached to its eye, desynchronizing its component of activity. On day 40, that optic lobe is removed (LOBX), eliminating the long period component.

from Wiedenmann [1136]


Figure 7.

Rhythms in electroretinogram (ERG) amplitude and efferent impulse activity in optic nerve of the horseshoe crab Limulus polyphemus. On the left is a schematic of the experimental arrangement. The ERG in response to a brief light pulse delivered via the light pipe was recorded from the left eye, while an electrode placed on the right optic nerve recorded efferent impulse activity. ERG amplitude (top) and efferent impulse frequency (bottom) show strongly correlated circadian rhythms.

from Barlow [41]


Figure 8.

In vitro rhythmicity in SCN explants. Upper panel: time histogram of firing frequency in a single SCN neuron. Lower panel: circadian oscillation of vasopressin release. (Upper figure; lower figure.)

adapted from Bos and Mirmiran [111] adapted from Murakami et al. [674]


Figure 9.

Transplantation of SCN tissue restores rhythmicity in SCN‐lesioned hosts, and the restored rhythm bears the period of the donor. Left panel shows the effect of transplanting SCN tissues from a 20 h period mutant donor into an SCN‐lesioned wild‐type host. Right panel shows the effect of transplanting SCN tissue from a wild‐type donor (period = 24 h) into an SCN‐lesioned heterozygote mutant host. Data in the left panel have been plotted at 20 h intervals to help visualize rhythmicity. SCNX, suprachiasmatic nucleus lesion; T, transplantation.

from Ralph et al. [767]


Figure 10.

Metabolic pathway describing pineal indoleamine derivatives of tryptophan. Enzymes: (1) tryptophan hydroxylase, (2) aromatic L‐amino acid decarboxylase, (3) N‐acetyltransferase, (4) monoamine oxidase, (5) aldehyde dehydrogenase, (6) hydroxyindole‐O‐methyltransferase.



Figure 11.

Schema of activity patterns showing effects of pinealectomy in three classes of vertebrate. Top panel: Columba livia (pigeon), Passer domesticus (house sparrow), Sturnus vulgaris (starling). Middle panel: Sceloporus olivaceus (Texas spiny lizard), Anolis carolinensis (green anole), Sceloporus occidentalis (Western fence lizard). Lower panel: Catostomus commersoni (white sucker), Heteropneustes fossilis (catfish), Lota lota (burbot). P, pinealectomized.



Figure 12.

Restoration of rhythmicity by transplantation of a pineal into the eye of a pinealectomized house sparrow. Donors' light cycles are diagrammed at the top of their respective records. Pinealectomized recipients were in DD.

from Zimmerman and Menaker [1165]


Figure 13.

In vitro patterns of melatonin secretion from individual pineal glands of the chicken Gallus domesticus, the green anole Anolis carolinensis, the desert iguana Dipsosaurus dorsalis, the pike Esox lucius, and the trout Salmo gairdneri. Left panels show melatonin patterns expressed under 24 h LD cycles and right panels show patterns expressed in DD.

adapted from Takahashi et al. [967] adapted from Menaker and Wisner [632] adapted from Janik and Menaker [496] adapted from Falcon et al. [290] adapted from Gern and Greenhouse [347]


Figure 14.

Melatonin infusion cycles with a period of 24.4 h entrain the feeding rhythm of a pinealectomized pigeon. The bird was held in DD and given 10 h of continuous melatonin (M) every 24.4 h.

from Chabot [172])


Figure 15.

Both light and temperature affect the pineal melatonin rhythm of reptiles. A: Annual changes in the daily rhythm of pineal melatonin content in the tortoise Testudo hermanni held under natural conditions of photoperiod and temperature (adapted from Vivien‐Roels et al. [1094]). B : Effects of amplitude reduction of a 24 h temprature cycle on the phase of the pineal melatonin rhythm of green anoles (Anolis carolinensis). Anoles were exposed to a temperature cycle in which the cool phase occurred during either day (left panel) or night (right panels). Pineal melatonin rhythm is entrained by the temperature cycle if the cycle is of high amplitude (32°/20°) but by the light cycle if the cycle is of low amplitude (32°/30°).

from Underwood [1036]


Figure 16.

Circadian rhythms of melatonin release from individual eyecups of the African clawed frog Xenopus laevis can be reset by light. Control eyecups (dashed lines) were held in DD and experimental eyecups (solid lines) were exposed to a 6 h pulse of white light during the times indicated at the top of each figure. Light pulses presented during the subjective day were without effect, pulses during the early part of the subjective night caused a delay in the phase of the rhythm, and pulses presented during the late subjective night caused an advance in the phase of the rhythm.

Adapted from Cahill and Besharse [145]


Figure 17.

Blinding by enucleation (EX) disrupts the circadian body temperature rhythm of Japanese quail. Actogram record (left panel) shows the body temperature rhythm of a blinded quail. The bird was rhythmic when held under LD 12:12 (diagrammed at the top of the figure) but became arrhythmic after being placed into DD. Right panels show results of F‐periodogram analysis of body temperature during LD (top) or DD (bottom): the bird was rhythmic under LD but arrhythmic under DD. By contrast, unoperated birds remained rhythmic in DD 1038.



Figure 18.

Extraretinal photoreceptors mediate entrainment in nonmammalian vertebrates. A: Entrainment of perch‐hopping activity of a blinded house sparrow to an LD 12:12 light cycle. At the point marked 1, the phase of the LD cycle was shifted, and at the point marked 2, the bird was exposed to DD (from Menaker [626]). B: Entertainment of a blinded Texas spiny lizard to an LD 12:12 light cycle.

from Underwood [1026]


Figure 19.

Models of mammalian (A) and nonmammalian (B) circadian systems. LGN, lateral geniculate nucleus; SCN, suprachiasmatic nucleus; RH, retinohypothalamic; ERR, extraretinal receptor.



Figure 20.

Activity feedback affects the circadian pacemaker of mammals. A: Representative activity records from hamsters free‐running in LL and given pulses of induced wheel‐running (between triangles) (from Reebs et al. [777]. B: Phase response curves for 30 min social interaction (top panel), cage changing (middle panel), and 2 h of novelty‐induced wheel‐running in hamsters.

adapted from Mrosovsky et al. [670]


Figure 21.

Daily feeding entrains a circadian oscillator in rats. The rat was fed for 2 h (marked with arrows) under LD 14:10, then placed into DD and presented with periods of feeding ad libitum (F) or food deprivation (N). The food‐associated rhythm persists in DD and can be discerned during periods of food deprivation but not during a libitum feeding.

adapted from Clarke and Coleman [186]


Figure 22.

Sample photoperiodic response curves: (A) pupal diapause of Yponomeuta vigintipunctatus 1084; (B) egg diapause of Aedes atropalpus 55; (C) adult diapause of Stenocranus minutus 672; (D) larval diapause of Carposina niponensis 1000.



Figure 23.

Effect of latitude (A) and temperature (B) on induction of larval diapause of Acronycta rumicis. The latitude from which the strain was collected and the temperature at which the experiment was conducted are given next to the appropriate photoperiodic response curve 212.



Figure 24.

Bünning's model for the photoperiodic clock. The photoperiodic time‐measuring system oscillates between periods of sensitivity (filled in part of the curve) and insensitivity to light. Upper panel depicts the rhythm free‐running under constant conditions and the two lower panels show the effects of a short day (middle panel) and a long day (bottom panel). If the days are long enough, they extend into the sensitive phase of the rhythm and a photoperiodic response is initiated.

adapted from Bünning [143]


Figure 25.

Positive and negative responses to the Nanda‐Hamner protocol. Various scotophases are combined with an 8 h photophase. Experimental LD cycles shown on bottom of figure. Positive response (dotted line) for diapause induction of the red spider mite Tetranychus urticae 1087. Note the periodic maxima approximately 24 h apart. Negative response (solid line) for virginopara production of Megoura viciae 565.



Figure 26.

Positive and negative responses to the night‐break protocol. A short photophase (8 or 12 h) is combined with a 64 h scotophase and 1 h light break during the extended night. Experimental LD cycles shown on bottom of figure. Positive response (dotted line) for Tetranychus urticae 1080. Note the periodic maxima approximately 24 h apart. Negative response (solid line) for Megoura viciae 567.



Figure 27.

Effects of transferring developing larvae of two species from long (L) to short (S) photoperiods, or short to long, at different stages of development. Numbers on abscissa refer to the instar during which the transfer was made. Note that the sensitive period appears to comprise the entire period of larval development and that the diapause‐averting effects of long days are greater than the diapause‐promoting effects of short days. Data for Antberaea pernyi from Tanaka 979 and those for Ostrinia nubilalis from Beck 58.



Figure 28.

Effect of temperature on induction of pupal diapause in Sarcophaga argyrostoma at LD 10:14, showing interaction between the sensitive period and the required day number. Polygons show the proportion of each batch of larvae forming puparia each day; shaded portions of polygons represent larvae which became diapausing pupae. Note that the sensitive period and the required day number have different temperature coefficients. At high temperatures (26° and 24°C), the sensitive period is shorter than the required day number and few, if any, of the pupae enter diapause, whereas the opposite is true at lower temperatures (14° and 16°C). Inset: Effect of temperature on proportion of diapause pupae at LD 10:14. Figure and legend from Saunders 867.



Figure 29.

Gonadal response and activity patterns of Syrian hamsters exposed to resonance and T‐experiment lighting protocols. A: Upper panel shows wheel‐running patterns of hamsters entrained to four different resonance light cycles; lower panel, testicular response to these light cycles. Cycles in which light impinged on the animals' subjective night were inductive (LD 6:30, LD 6:54), whereas cycles in which light impinged only on the subjective day (LD 6:18, LD 6:42) were not (from Elliott et al. [277]). B: Upper panel shows wheel‐running activity of hamsters entrained to three different light cycles using 1 h light pulses. Line connects midpoints of 1 h light pulses. Lower panel shows testicular response to various T‐cycles (1 h light pulses). Photoperiodic stimulation of testicular growth is dependent on the position of the 1 h light pulse relative to the circadian system. Testicular growth occurs only if the light pulse entrains the circadian system such that light falls during subjective night (that is, the sensitive phase of Bünning's rhythm).

from Elliott [273]


Figure 30.

Action spectrum for the extraretinal photoreceptors mediating the photoperiodic response in Japanese quail; LH, luteinizing hormone.

adapted from Foster et al. [321]


Figure 31.

Maternal transfer of photoperiodic information to pups in utero. Figures show paired testes weights of Djungarian hamsters gestated and raised on the indicated photoperiods. The postnatal photoperiod is stimulatory or not depending on the photoperiod experienced by the mother during pregnancy.

adapted from Stetson et al. [944]


Figure 32.

Effects of pinealectomy and melatonin infusion on the annual reproductive cycle of sheep. Timing of high luteinizing hormone stages (horizontal solid bars) becomes uncoupled from the environment after pinealectomy (left panel), but short‐day (SD Mel, batched vertical box) and long‐day (LD Mel, open box) melatonin infusions entrain the reproductive cycle of pinealectomized ewes

adapted from Woodfill et al. [1149]
References
 1. Abe, H., M. Kida, K. Tsuji, and T. Mano. Feeding cycles entrain circadian rhythms of locomotor activity in CS mice but not in C57BL/6J mice. Physiol. Behav. 45: 397–401, 1989.
 2. Abe, H., B. Rusak, and H. A. Robertson. Photic induction of fos protein in the suprachiasmatic nucleus is inhibited by the NMDA receptor antagonist MK‐801. Neurosci. Lett. 127: 9–12, 1991.
 3. Abe, H., B. Rusak, and H. A. Robertson. NMDA and non‐NMDA receptor antagonists inhibit photic induction of Fos protein in the hamster suprachiasmatic nucleus. Brain Res. Bull. 28: 831–835, 1992.
 4. Abe, H., and T. Y. Yamamoto. Diurnal changes in synaptic ribbons of rod cells of the turtle. J. Ultrastruct. Res. 86: 246–251, 1984.
 5. Adler, H. E. Sensory factors in migration. Anim. Behav. 11: 566–577, 1963.
 6. Adler, K. Pineal end organ: role in extraoptic entrainment of circadian locomotor rhythm in frogs. In: Biochronometry, edited by M. Menaker. Washington, DC: National Academy of Sciences, 1971, p. 342–350.
 7. Albers, H. E. Gonadal hormones organize and modulate the circadian system of the rat. Am. J. Physiol. 241 (Regulatory Integrative Comp. Physiol. 12): R62–R66, 1981.
 8. Albers, H. E., and C. F. Ferris. Neuropeptide Y: role in light‐dark cycle entrainment of hamster circadian rhythms. Neurosci. Lett. 50: 163–168, 1984.
 9. Albers, H. E., A. A. Gerall, and J. F. Axelson. Effect of reproductive state on circadian periodicity in the rat. Physiol. Behav. 26: 21–25, 1981.
 10. Albers, H. E., S.‐Y. Liou, C. F. Ferris, E. G. Stopa, and R. T. Zoeller. Neurochemistry of circadian timing. In: Suprachiasmatic Nucleus. The Mind's Clock, edited by D. C. Klein, R. Y. Moore, and S. M. Reppert. New York: Oxford Univ. Press, 1991, p. 263–288.
 11. Albers, H. E., S.‐Y. Liou, E. G. Stopa, and R. T. Zoeller. Interaction of colocalized neuropeptides: functional significance in the circadian timing system. J. Neurosci. 11: 846–851, 1991.
 12. Albers, H. E., N. Minamitani, E. Stopa, and C. F. Ferris. Light selectively alters vasoactive intestinal peptide and peptide histidine isoleucine immunoreactivity within the rat suprachiasmatic nucleus. Brain Res. 437: 189–192, 1987.
 13. Albers, H. E., J. E. Ottenweller, S. Y. Liou, M. D. Lumpkin, and E. R. Anderson. Neuropeptide Y in the hypothalamus: effect on corticosterone and single‐unit activity. Am. J. Physiol. 258 (Regulatory Integrative Comp. Physiol. 29): R376–R382, 1990.
 14. Alleva, J. J., M. V. Waleski, and F. R. Alleva. A biological clock controlling the estrous cycle of the hamster. Endocrinology 88: 1368–1379, 1971.
 15. Almeida, O.F.X., and G. A. Lincoln. Photoperiodic regulation of reproductive activity in the ram: evidence for the involvement of circadian rhythms in melatonin and prolactin secretion. Biol. Reprod. 27: 1062–1075, 1982.
 16. Alonso‐Bedate, M., M. J. Delgado, and R. Carballada. In vivo effect of melatonin and gonadotropin‐releasing hormone on testicular function in Rana temporaria. J. Pineal Res. 5: 323–332, 1988.
 17. Alonso‐Gómez, A. L., M. Tejera, M. Alonso‐Bedate, and M. J. Delgado. Response to pinealectomy and blinding in vitellogenic female frogs (Rana perezi) subjected to high temperature in autumn. Can. J. Physiol. Pharmacol. 68: 94–98, 1990.
 18. Altman, J., and S. A. Bayer. The development of the rat hypothalamus. Adv. Anat. Embryol. Cell Biol. 100: 1–178, 1986.
 19. Anderson, K., and F. Turek. The influence of blinding and removal of the frontal organ on the activity of Xenopus laevis. Am. Zool. 23: 884, 1983.
 20. Anis, Y., I. Nir, and N. Zisapel. Diurnal variations in melatonin binding sites in the hamster brain: impact of melatonin. Mol. Cell. Endocrinol. 67: 121–129, 1989.
 21. Aréchiga, H., J. L. Cortes, U. Garcia, and L. Rodriguez‐Sosa. Neuroendocrine correlates of circadian rhythmicity in crustaceans. Am. Zool. 25: 265–274, 1985.
 22. Arendt, J. Role of the pineal gland and melatonin in seasonal reproductive function in mammals. In: Oxford Reviews of Reproductive Biology, edited by J. R. Clarke. Oxford: Clarendon, 1986, p. 266–320.
 23. Aronin, N., S. M. Sagar, F. R. Sharp, and W. J. Schwartz. Light regulates expression of a Fos‐reilated protein in rat suprachiasmatic nuclei. Proc. Natl. Acad. Sci. U.S.A. 87: 5959–5962, 1990.
 24. Aronin, N., and W. J. Schwartz. A new strategy to explore molecular mechanisms of suprachiasmatic nucleus function. In: Suprachiasmatic Nucleus. The Mind's Clock, edited by D. C. Klein, R. Y. Moore, and S. M. Reppert. New York: Oxford Univ. Press, 1991, p. 445–456.
 25. Aschoff, J. Exogenous and endogenous components in circadian rhythms. Cold Spiring Harbor Symp. Quant. Biol. 25: 11–28, 1960.
 26. Aschoff, J. Response curves in circadian periodicity. In: Circadian Clocks, edited by J. Aschoff. Amsterdam: North‐Holland, 1965, p. 95–111.
 27. Aschoff, J. Circadian rhythms: influences of internal and external factors on the period measured in constant conditions. Z. Tierpsychol. 49: 225–249, 1979.
 28. Aschoff, J., J. Figala, and E. Poppel. Circadian rhythms of locomotor activity in the golden hamster (Mesocricetus auratus) measured with two different techniques. J. Comp. Physiol. Psychol. 85: 20–28, 1973.
 29. Aschoff, J., U. Gerecke, C. von Goetz, G. A. Groos, and F. W. Turek. Phase responses and characteristics of free‐running activity rhythms in the golden hamster: independence of the pineal gland. In: Vertebrate Circadian Systems, edited by J. Aschoff, S. Daan, and G. Groos. Berlin: Springer‐Verlag, 1982, p. 129–140.
 30. Aschoff, J., and C. von Goetz. Effects of feeding cycles on circadian rhythms in squirrel monkeys. J. Biol. Rhythms 1: 267–276, 1986.
 31. Aschoff, J., C. von Goetz, and K. Honma. Restricted feeding in rats: effects of varying feeding cycles. Z. Tierpsychol. 63: 91–111, 1983.
 32. Badura, L. L., and B. D. Goldman. Seasonal regulation of neuroendocrine activity in male Turkish hamsters (Mesocricetus brandti): role of the hypothalamic paraventricular nucleus. Neuroendocrinology 55: 477–484, 1992.
 33. Baggerman, B. Photoperiodic responses in the stickleback and their control by a daily rhythm of photosensitivity. Gen. Comp. Endocrinol. Suppl. 3: 466–476, 1972.
 34. Baggerman, B. Photoperiodic and endogenous control of the annual reproductive cycle in teleost fishes. In: Environmental Physiology of Pishes, edited by M. A. Ali. New York: Plenum, 1980, p. 533–567.
 35. Bährmann, R. Untersuchungen zur populationsdynamik von Aleyrodes asari Schrank und Aleurolobus asari Wunn (Homoptera, Aleyrodina). Zool. Jahrbuecher Syst. 99: 82–106, 1972.
 36. Baily, S.E.R. Circannual and circadian rhythms in the snail Helix aspersa Muller and the photoperiodic control of annual activity and reproduction. J. Comp. Physiol. 142: 89–94, 1981.
 37. Baker, J. R. The evolution of breeding seasons. In: Evolution: Essays on Aspects of Evolutionary Biology, edited by G. R. de Beer. London: Oxford Univ. Press, 1938, p. 161–177.
 38. Balasubramanian, K. S., and R. N. Saxena. Effect of pinealectomy and photoperiodism in the reproduction of Indian weaver birds, Ploceus philippinus. J. Exp. Zool. 185: 333–340, 1973.
 39. Bale, J. S. Insect cold hardiness: freezing and supercooling—an ecological perspective. J. Insect Physiol. 33: 899–908, 1987.
 40. Barker, R. J., and C. F. Cohen. Light‐dark cycles and diapause induction in Pieris rapae (L.). Entomol. Exp. Appl. 8: 27–32, 1965.
 41. Barlow, R. B., Jr. Circadian rhythms in the Limulus visual system. J. Neurosci. 3: 856–870, 1983.
 42. Barlow, R. B., Jr., S. J. Balanowski, Jr., and M. L. Brachman. Efferent optic nerve fibers mediate circadian rhythms in the Limulus eye. Science 197: 86–89, 1977.
 43. Barlow, R. B., Jr., E. Kaplan, G. H. Renninger, and T. Saito. Efferent control of circadian rhythms in Limulus lateral eye. Neurosci. Res. Suppl. 2: S65–S78, 1985.
 44. Barnes, B. M., and A. D. York. Effect of winter high temperatures on reproduction and circannual rhythms in hibernating ground squirrels. J. Biol. Rhythms 5: 119–130, 1990.
 45. Barrera‐Mera, B. The effect of cerebroid ganglion lesions on ERG circadian rhythm in the crayfish. Physiol. Behav. 17: 59–64, 1976.
 46. Barrett, R. K., and T. L. Page. Effects of light on circadian pacemaker development. I. The freerunning period. J. Comp. Physiol. [A] 165: 41–49, 1989.
 47. Barrett, R. K., and H. Underwood. Retinally perceived light can entrain the pineal melatonin rhythm in Japanese quail. Brain Res. 563: 87–93, 1991.
 48. Barrett, R. K., and H. Underwood. The superior cervical ganglia are not necessary for entrainment or persistence of the pineal melatonin rhythm in Japanese quail. Brain Res. 569: 249–254, 1992.
 49. Bartness, T. J., E. L. Bittman, and G. N. Wade. Paraventricular nucleus lesions exaggerate dietary obesity but block photoperiod‐induced weight gains and suspension of estrous cyclicity in Syrian hamsters. Brain Res. Bull. 14: 427–430, 1985.
 50. Bartness, T. J., and B. D. Goldman. Effects of melatonin on long‐day responses in short‐day housed adult Siberian hamsters. Am. J. Physiol. 255 (Regulatory Integrative Comp. Physiol. 26): R823–R830, 1988.
 51. Bartness, T. J., and B. D. Goldman. Peak duration of serum melatonin and short‐day responses in adult Siberian hamsters. Am. J. Physiol. 255 (Regulatory Integrative Comp. Physiol. 26): R812–R822, 1988.
 52. Bartness, T. J., B. D. Goldman, and E. L. Bittman. SCN lesions block responses to systemic melatonin infusions in Siberian hamsters. Am. J. Physiol. 260 (Regulatory Integrative Comp. Physiol. 31): R102–R112, 1991.
 53. Bartness, T. J., and G. N. Wade. Photoperiodic control of body weight and energy metabolism in Syrian hamsters (Mesocricetus auratus): role of pineal gland, melatonin, gonads and diet. Endocrinology 114: 492–498, 1984.
 54. Baylé, J. D., J. Oliver, and B. Sicard. An ocular capacity to promote photoperiodic testicular growth in the quail. J. Endocrinol. 96: 85–90, 1983.
 55. Beach, R. F., and G. B. Craig. Night length measurements by the circadian clock controlling diapause induction in the mosquito Aedes atropalpus. J. Insect Physiol. 23: 865–870, 1977.
 56. Beasley, L. J., and R. J. Nelson. Thyroid gland influences the period of hamster circadian oscillations. Experientia 38: 870–871, 1982.
 57. Beck, S. D. Photoperiodic induction of diapause in an insect. Biol. Bull. Marine Biol. Lab. Woods Hole 122: 1–12, 1962.
 58. Beck, S. D. Insect Photoperiodism. New York: Academic, 1968.
 59. Beck, S. D. Photoperiodic determination of insect development and diapause. I. Oscillators, hourglasses and a determination model. J. Comp. Physiol. 90: 275–295, 1974.
 60. Beck, S. D. Photoperiodic determination of insect development and diapause. 11. The determination gate in a theoretical model. J. Comp. Physiol. 90: 297–310, 1974.
 61. Beck, S. D. Photoperiodic determination of insect development and diapause. HI. Effects of non‐diel photoperiods. J. Comp Physiol. 103: 227–245, 1975.
 62. Beck, S. D. Photoperiodic determination of insect development and diapause. IV. Effects of skeleton photoperiods. J. Comp Physiol. 105: 267–277, 1976.
 63. Beck, S. D. Photoperiodic determination of insect development and diapause. V. Diapause, circadian rhythms, and phase response curves, according to the dual system theory. J. Comp Physiol. 107: 97–111, 1976.
 64. Beck, S. D. Dual system theory of the biological clock: effects of photoperiod, temperature, and thermoperiod on the determination of diapause. J. Insect Physiol. 23: 1363–1372, 1977.
 65. Beck, S. D. Insect thermoperiodism. Annu. Rev. Entomol. 28: 91–108, 1983.
 66. Beck, S. D., and W. Hanec. Diapause in the European corn borer, Pyrausta nubilalis. J. Insect Physiol. 4: 304–318, 1960.
 67. Behrens, W. Environmental aspects of insect dormancy. In: Environmental Physiology and Biochemistry of Insects, edited by Klaus Hoffman. Berlin: Springer‐Verlag, 1985, p. 67–94.
 68. Beiswanger, C. M., P. G. Sokolove, and D. J. Prior. Extraocular photoentrainment of the circadian locomotor rhythm of the garden slug Limax. J. Comp. Physiol. 216: 13–23, 1981.
 69. Benoit, J. Stimulation par la lumière artificielle du développement testiculaire chez des canards aveuglés par section du nerf optique (avec demonstrations). C. R. Soc. Biol. 120: 133–136, 1935.
 70. Benoit, J. The role of the eye and of the hypothalamus in the photostimulation of gonads in the duck. Ann. N. Y. Acad. Sci. 117: 204–215, 1964.
 71. Benoit, J. Étude de Taction des radiations visibles de différentes longueurs d'onde sur la gonadostimulation et de leur pénétration transcranienne chez les oiseaux et les mammiferes. In: Colloque International du CNRS sur la Photorégulation de la Reproduction chez les Oiseaux et les Mammiferes, edited by J. Benoit and I. Assenmacher. Paris: Centre National de la Recherche Scientifique, 1970, p. 121–149.
 72. Benoit, J., I. Assenmacher, and S. Manuel. Penetration des radiations visibles jusqu'a l'encéphale à travers la région orbitaire chez le canard. Sa mesure par un procédé photographique. C. R. Soc. Biol. 147: 40–44, 1953.
 73. Benson, B., and I. Ebels. Other pineal peptides and related substances—physiological implications for reproductive biology. In: The Pineal Gland. VII. Reproductive Effects, edited by R. J. Reiter. Boca Raton, FL: CRC, 1981, p. 165–187.
 74. Berria, M., M. Desantis, and R. A. Mead. Effects of suprachiasmatic nuclear ablation and melatonin on delayed implantation in the spotted skunk. Neuroendocrinology 48: 371–375, 1988.
 75. Berria, M., M. Desantis, and R. A. Mead. Testicular response to melatonin or suprachiasmatic nuclei ablation in the spotted skunk. J. Exp. Zool. 255: 72–79, 1990.
 76. Besharse, J. C., and D. A. Dunis. Methoxyindoles and photoreceptor metabolism: activation of rod shedding. Science 219: 1341–1343, 1983.
 77. Besharse, J. C., and P. M. Iuvone. Circadian clock in Xenopus eye controlling retinal serotonin N‐acetyltransferase. Nature 305: 133–135, 1983.
 78. Biebach, H., M. Gordijn, and J. R. Krebs. Time‐and‐place learning by garden warblers (Sylvia borin). Anim. Behav. 37: 353–360, 1989.
 79. Binkley, S., and E. B. Geller. Pineal enzymes in chickens: development of daily rhythmicity. Gen. Comp. Endocrinol. 27: 424–429, 1975.
 80. Binkley, S., and K. Mosher. Two circadian rhythms in pairs of sparrows. J. Biol. Rhythms 3: 249–254, 1988.
 81. Binkley, S. A., J. B. Riebman, and K. B. Reilly. The pineal gland: a biological clock in vitro. Science 202: 1198–1201, 1978.
 82. Bittman, E. L. Hamster refractoriness: the role of insensitivity of pineal target tissues. Science 202: 648–650, 1978.
 83. Bittman, E. L., T. J. Bartness, B. D. Goldman, and G. J. Devries. Suprachiasmatic and paraventricular control of photoperiodism in Siberian hamsters. Am. J. Physiol. 260 (Regulatory Integrative Comp. Physiol. 31): R90–R101, 1991.
 84. Bittman, E. L., R. G. Crandell, and M. N. Lehman. Influences of the paraventricular and suprachiasmatic nuclei and olfactory bulbs on melatonin responses in the golden hamster. Biol. Reprod. 40: 118–126, 1989.
 85. Bittman, E. L., B. D. Goldman, and I. Zucker. Testicular responses to melatonin are altered by lesions of the suprachiasmatic nuclei in golden hamsters. Biol. Reprod. 21: 647–656, 1979.
 86. Bittman, E. L., and F. J. Karsch. Nightly duration of pineal melatonin secretion determines the reproductive response to inhibitory day length in the ewe. Biol. Reprod. 30: 585–593, 1984.
 87. Bittman, E. L., F. J. Karsch, and J. W. Hopkins. Role of the pineal gland in ovine photoperiodism: regulation of seasonal breeding and negative feedback effects of estradiol upon luteinizing hormone secretion. Endocrinology 113: 329–336, 1983.
 88. Bittman, E. L., A. H. Kaynard, D. H. Olster, J. E. Robinson, S. M. Yellon, and F. J. Karsch. Pineal melatonin mediates photoperiodic control of pulsatile luteinizing hormone secretion in the ewe. Neuroendocrinology 40: 409–418, 1985.
 89. Bittman, E. L., and M. N. Lehman. Paraventricular neurons control hamster photoperiodism by a predominantly uncrossed descending pathway. Brain Res. Bull. 19: 687–694, 1987.
 90. Bittman, E. L., and D. R. Weaver. The distribution of melatonin binding sites in neuroendocrine tissues of the ewe. Biol. Reprod. 43: 986–993, 1990.
 91. Bittman, E. L., and I. Zucker. Photoperiodic termination of hamster refractoriness: participation of the pineal gland. Biol. Reprod. 24: 568–572, 1981.
 92. Blake, G. M. Diapause and the regulation of development in Anthrenus verbasi (L.) (Col., Dermestidae). Bull. Entomol. Res. 49: 751–775, 1958.
 93. Blake, G. M. Control of diapause by an “internal clock” in Anthrenus verbasi (L.) (Col., Dermestidae). Nature 183: 126–127, 1959.
 94. Blake, G. M. Decreasing photoperiod inhibiting metamorphosis in an insect. Nature 188: 168–169, 1960.
 95. Blake, G. M. Shortening of a diapause‐controlled life cycle by means of increasing photoperiod. Nature 198: 462–463, 1963.
 96. Block, G. D., and P. A. Davenport. Switch from nocturnal to diurnal behavior in the cloudy bubble snail Bulla gouldiana. J. Exp. Zool. 244: 57–63, 1982.
 97. Block, G. D., D. J. Hudson, and M. E. Lickey. Extraocular photoreceptors can entrain the circadian oscillator in the eye of Aplysia. J. Comp. Physiol. 89: 237–250, 1974.
 98. Block, G. D., S. Khalsa, S. Michel, M. Geusz, and D. McMahon. Cellular bzisis of biological timekeeping. Int. Rev. Cytol. 146: 83–144, 1993.
 99. Block, G. D., V. G. McMahon, S. Wallace, and W. Friesen. Cellular analysis of the ocular circadian pacemaker system: a model for retinal organization. J. Comp. Physiol. [A] 155: 365–378, 1984.
 100. Block, G. D., and T. L. Page. Effects of efferent activity on entrainment of the Aplysia eye. Comp. Biochem. Physiol. A 62: 635–638, 1978.
 101. Block, G. D., and M. H. Roberts. Circadian pacemaker in the Bursatella eye: properties of the rhythm and its effect on locomotor behavior. J. Comp. Physiol. 142: 403–410, 1981.
 102. Block, G. D., M. H. Roberts, and A. E. Lusska. Cellular analysis of circadian pacemaker coupling in Bulla. J. Biol. Rhythms 1: 199–217, 1986.
 103. Block, G. D., and S. Wallace. Localization of a circadian pacemaker in the eye of a mollusk, Bulla. Science 217: 155–157, 1982.
 104. Boer, G. J., and H. A. Griffioen. Developmental and functional aspects of grafting of the suprachiasmatic nucleus in the Brattleboro and the arhythmic rat. Eur. J. Morphol. 28: 330–345, 1990.
 105. Boissin‐Agasse, L., J. Boissin, and R. Ortavant. Circadian photosensitive phase and photoperiodic control of testis activity in the mink (Mustela vison Peale and Beauvois), a short‐day mammal. Biol. Reprod. 26: 110–119, 1982.
 106. Bonnefond, C., L. Martinet, and R. Monnerie. Effects of timed melatonin infusions and lesions of the suprachiasmatic nuclei on prolactin and progesterone secretions in pregnant or pseudopregnant mink (Mustela vison). J. Neuroendocrinal. 2: 583–591, 1990.
 107. Bonnefond, C., P. P. Walker, J. A. Stutz, E. Maywood, T. S. Juss, J. Herbert, and M. H. Hastings. The hypothalamus and photoperiodic control of FSH secretion by melatonin in the male Syrian hamster. J. Endocrinol. 122: 247–254, 1989.
 108. Borbely, A. A. Circadian and sleep‐dependent processes in sleep regulation. In: Vertebrate Circadian Systems, edited by J. Aschoff, S. Daan, and G. Groos. Berlin: Springer‐Verlag, 1982, p. 237–242.
 109. Borg, B. Extraretinal photoreception involved in photoperiodic effects on reproduction in male three‐spined sticklebacks, Gasterosteus aculeatus. Gen. Comp. Endocrinol. 47: 84–87, 1982.
 110. Borg, B., and P. Ekstrom. Gonadal effects of melatonin in the three‐spined stickleback, Gasterosteus aculeatus L., during different seasons and photoperiods. Reprod. Nutr. Dev. 21: 919–927, 1981.
 111. Bos, N.P.A., and M. Mirmiran. Circadian rhythms in spontaneous neuronal discharges of the cultured suprachiasmatic nucleus. Brain Res. 511: 158–162, 1990.
 112. Bosc, M. J. Time of parturition in rats after melatonin administration or change of photoperiod. J. Reprod. Fertil. 80: 563–568, 1987.
 113. Bosc, M. J. Photoperiodic regulation of the time of birth in rats: involvement of circadian endogenous mechanisms. Physiol. Behav. 48: 441–446, 1990.
 114. Boulos, Z., D. M. Frim, L. K. Dewey, and M. C. Moore‐Ede. Effects of restricted feeding schedules on circadian organization in squirrel monkeys. Physiol. Behav. 45: 507–515, 1989.
 115. Boulos, Z., and D. E. Logothetis. Rats anticipate and discriminate between two daily feeding times. Physiol. Behav. 48: 523–529, 1990.
 116. Boulos, Z., A. M. Rosenwasser, and M. Terman. Feeding schedules and the circadian organization of behavior in the rat. Behav. Brain Res. 1: 39–65, 1980.
 117. Boulos, Z., and B. Rusak. Circadian phase response curves for dark pulses in the hamster. J. Comp. Physiol. 146: 411–417, 1982.
 118. Boulos, Z., and M. Terman. Food availability and daily biological rhythms. Neurosci. Biobehav. Rev. 4: 119–131, 1980.
 119. Bovet, J., and E. F. Oertli. Free‐running circadian activity rhythms in free‐living beaver (Castor canadensis). J. Comp. Physiol. 92: 1–10, 1974.
 120. Bowen, M. F. Photoperiodic Time Measurement in Ostrinia nubilalis. Newark: Univ. of Delaware, 1976. Dissertation.
 121. Bowen, M. F., W. E. Bollenbacher, and L. I. Gilbert. In vitro studies on the role of the brain and prothoracic glands in the pupal diapause of Manduca sexta. J. Exp. Biol. 108: 9–24, 1984.
 122. Bowen, M. F., D. S. Saunders, W. E. Bollenbacher, and L. I. Gilbert. In vitro reprogramming of the photoperiodic clock in an insect brain‐retrocerebral complex. Proc. Natl. Acad. Sci. U.S.A. 81: 5881–5884, 1984.
 123. Bowen, M. F., and S. D. Skopik. Insect photoperiodism: the “T‐experiment” as evidence for an hourglass mechanism. Science 192: 59–60, 1976.
 124. Brackmann, M., and K. Hoffmann. Pinealectomy and photoperiod influence testicular development in the Djungarian hamster. Naturwissenschaften 64: 341, 1977.
 125. Bradshaw, W. E. Action spectra for photoperiodic response in a diapausing mosquito. Science 175: 1361–1362, 1972.
 126. Brady, J. Circadian changes in central excitability: the origin of behavioral rhythms in tsetse flies and other animals? J. Entomol. 50: 79–95, 1975.
 127. Brainard, G. C., A. J. Lewy, M. Menaker, R. H. Fredrickson, L. S. Miller, R. G. Weleber, V. Cassone, and D. Hudson. Dose‐response relationship between light irradiance and the suppression of plasma melatonin in human volunteers. Brain Res. 454: 212–218, 1988.
 128. Brainard, G. C., B. A. Richardson, T. S. King, and R. J. Reiter. The influence of different light spectra on the suppression of pineal melatonin content in the Syrian hamster. Brain Res. 294: 333–339, 1984.
 129. Brainard, G. C., M. D. Rollag, B. A. Northrup, C. Cole, and F. M. Barker. The influence of light irradiance and wavelength on pineal physiology of mammals. In: Pineal and Retinal Relationships, edited by P. J. O'Brien and D. C. Klein. New York: Academic, 1986, p. 235–277.
 130. Brann, M. R., and L. V. Cohen. Diurnal expression of transducin mRNA and translocation of transducin in rods of rat retina. Science 235: 585–587, 1987.
 131. Brinkmann, K. Discussion to the paper of D. K. Hayes. In: Biochronometry, edited by M. Menaker. Washington, DC: National Academy of Sciences, 1971, p. 401–402.
 132. Brock, M. A. Circannual rhythms in invertebrates. In: Circan nual Rhythms, edited by E. T. Pengelley. New York: Academic, 1974, p. 11–53.
 133. Brock, M. A. Circannual rhythms I. Free‐running rhythms in growth and development of the marine cnidarian, Campanularia flexuosa. Comp. Biochem. Physiol. A51: 377–383, 1975.
 134. Brock, M. A. Circannual rhythms II. Temperature‐compensated free‐running rhythms in growth and development of the marine cnidarian, Campanularia flexuosa. Comp. Biochem. Physiol. A 51: 377–383, 1975.
 135. Brock, M. A. Circannual rhythms III. Rhythmicity in the longevity of hydranths of the marine cnidarian, Campanularia flexuosa. Comp. Biochem. Physiol. A51: 391–398, 1975.
 136. Bromage, N., J. Duston, C. Randall, A. Brook, M. Thrush, M. Carrillo, and S. Zanuy. Photoperiodic control of teleost reproduction. In: Progress in Comparative Endocrinology, edited by A. Epple, C. G. Scanes, and M. H. Stetson. New York: Wiley‐Liss, 1990, p. 620–626.
 137. Bronstein, D. M., G. H. Jacobs, K. A. Haak, J. Neitz, and L. D. Lytle. Action spectrum of the retinal mechanism mediating nocturnal light‐induced suppression of rat pineal gland N‐acetyltransferase. Brain Res. 406: 352–356, 1987.
 138. Brown, F. A., Jr., J. W. Hastings, and J. D. Palmer. The Biological Clock: Two Views. New York: Academic, 1970.
 139. Brown, V. K. The overwintering stages of Ectobius lapponicus (L.) (Dictyoptera: Blattidae). J. Entomol. 48: 11–24, 1973.
 140. Brown, V. K. Developmental strategies in Ectobius pallidus (Dictyoptera: Blattidae). Int. J. Invertebr. Reprod. 2: 85–93, 1980.
 141. Buchanan, K. L., and S. M. Yellon. Delayed puberty in the male Djungarian hamster: effect of short photoperiod or melatonin treatment on the GnRH neuronal system. Neuroendocrinology 54: 96–102, 1991.
 142. Bünning, E. Die endogene Tagesrhythmik als Grundlage der photoperiodischen Reaktion. Berl. Dtsch. Bot. Ges. 54: 590–607, 1936.
 143. Bünning, E. Orcadian rhythms and the time measurement in photoperiodism. Cold Spring Harbor Symp. Quant. Biol. 25: 249–256, 1960.
 144. Bünning, E. The Physiological Clock. Berlin: Springer‐Verlag, 1973.
 145. Cahill, G. M., and J. C. Besharse. Resetting the circadian clock in Xenopus eyecups: regulation of retinal melatonin rhythms by light and D2 dopamine receptors. J. Neurosci. 11: 2959–2971, 1991.
 146. Cahill, G. M., M. S. Grace, and J. C. Besharse. Rhythmic regulation of retinal melatonin: metabolic pathways, neurochemical mechanisms, and the ocular circadian clock. Cell. Mol. Neurobiol. 11: 529–560, 1991.
 147. Cahill, G. M., and M. Menaker. Kynurenic acid blocks suprachiasmatic nucleus responses to optic nerve stimulation. Brain Res. 410: 125–129, 1987.
 148. Cahill, G. M., and M. Menaker. Responses of the suprachiasmatic nucleus to retinohypothalamic tract volleys in a slice preparation of the mouse hypothalamus. Brain Res. 479: 65–75, 1989.
 149. Cahill, G. M., and M. Menaker. Effects of excitatory amino acid receptor antagonists and agonists on suprachiasmatic nucleus responses to retinohypothalamic tract volleys. Brain Res. 479: 76–82, 1989.
 150. Calza, L., L. Giardino, M. Zanni, A. Velardo, P. Parchi, and P. Marrama. Daily changes of neuropeptide Y‐like immunore‐activity in the suprachiasmatic nucleus of the rat. Regul. Pept. 27: 127–137, 1990.
 151. Canbeyli, R. S., M. Lehman, and R. Silver. Tracing SCN graft efferents with dil. Brain Res. 554: 15–21, 1991.
 152. Card, J. P., and R. Y. Moore. The organization of visual circuits influencing the circadian activity of the suprachiasmatic nucleus. In: Suprachiasmatic Nucleus. The Mind's Clock, edited by D. C. Klein, R. Y. Moore, and S. M. Reppert. New York: Oxford Univ. Press, 1991, p. 51–76.
 153. Cardé, R. T., A. M. Shapiro, and H. K. Clench. Sibling species in the eurydice group of Lethe (Lepidoptera: Satyridae). Psyche 77: 70–103, 1970.
 154. Cardinali, D. P., A. E. Cuello, J. H. Tramezzani, and J. M. Rosner. Effects of pinealectomy on the testicular function of the adult male duck. Endocrinology 89: 1082–1093, 1971.
 155. Cardinali, D. P., F. Larin, and R. J. Wurtman. Action spectra for effects of light on hydroxyindole‐O‐methyltransferase in rat pineal, retina and Harderian gland. Endocrinology 91: 877–886, 1972.
 156. Cardinali, D. P., F. Larin, and R. J. Wurtman. Control of the rat pineal gland by light spectra. Proc. Natl. Acad. Sci. U.S.A. 69: 2003–2005, 1972.
 157. Carlson, L. L., D. R. Weaver, and S. M. Reppert. Melatonin signal transduction in hamster brain: inhibition of adenylyl cyclase by a pertussis toxin‐sensitive G protein. Endocrinology 125: 2670–2676, 1989.
 158. Carlson, L. L., D. R. Weaver, and S. M. Reppert. Melatonin receptors and signal transduction during development in Siberian hamsters (Phodopus sungorus). Dev. Brain Res. 59: 83–88, 1991.
 159. Carmichael, M. S., and I. Zucker. Circannual rhythms of ground squirrels: a test of the frequency demultiplication hypothesis. J. Biol. Rhythms 1: 277–284, 1986.
 160. Carter, D. S., and B. D. Goldman. Anti‐gonadal effects of timed melatonin infusions in pinealectomized male Djungarian hamsters (Phodopus sungorus sungorus): duration is the critical parameter. Endocrinology 113: 1261–1267, 1983.
 161. Carter, D. S., and B. D. Goldman. Progonadal role of the pineal in the Djungarian hamster (Phodopus sungorus sungorus): mediation by melatonin. Endocrinology 113: 1268–1273, 1983.
 162. Carter, D. S., V. D. Hall, L. Tamarkin, and B. D. Goldman. Pineal is required for testicular maintenance in the Turkish hamster (Mesocricetus brandti). Endocrinology 111: 863–871, 1982.
 163. Cassone, V. M. Effects of melatonin on vertebrate circadian systems. Trends Neurosci. 13: 457–464, 1990.
 164. Cassone, V. M., and D. S. Brooks. The sites of melatonin action in the brain of the house sparrow, Passer domesticus. J. Exp. Zool. 260: 302–309, 1991.
 165. Cassone, V. M., M. J. Chesworth, and S. M. Armstrong. Dose‐dependent entrainment of rat circadian rhythms by daily injection of melatonin. J. Biol. Rhythms 1: 219–229, 1986.
 166. Cassone, V. M., M. J. Chesworth, and S. M. Armstrong. Entrainment of rat circadian rhythms by daily injections of melatonin depends upon the hypothalamic suprachiasmatic nuclei. Physiol. Behav. 36: 1111–1121, 1986.
 167. Cassone, V. M., A. M. Forsyth, and G. L. Woodlee. Hypothalamic regulation of circadian noradrenergic input to the chick pineal gland. J. Comp. Physiol. [A] 167: 187–192, 1990.
 168. Cassone, V. M., and M. Menaker. Sympathetic regulation of chicken pineal rhythms. Brain Res. 272: 311–317, 1983.
 169. Cassone, V. M., and R. Y. Moore. The retinohypothalamic projection and suprachiasmatic nucleus of the house sparrow, Passer domesticus. J. Comp. Neurol. 266: 171–182, 1987.
 170. Cassone, V. M., M. H. Roberts, and R. Y. Moore. Melatonin inhibits metabolic activity in the rat suprachiasmatic nuclei. Neurosci. Lett. 81: 29–34, 1987.
 171. Cassone, V. M., J. C. Speh, J. P. Card, and R. Y. Moore. Comparative anatomy of the mammalian suprachiasmatic nucleus. J. Biol. Rhythms 3: 71–91, 1988.
 172. Chabot, C. Melatonin Regulation of Feeding and Locomotor Rhythms in the Pigeon, Columba livia. Charlottesville: Univ. of Virginia, 1990. Dissertation.
 173. Chabot, C. C., and M. Menaker. Effects of physiological cycles of infused melatonin on circadian rhythmicity in pigeons. J. Comp. Physiol. [A] 170: 615–622, 1992.
 174. Chan, K. A photosensitivity daily rhythm in the female medaka. Can. J. Zool. 54: 852–856, 1976.
 175. Chanda, S., and N. W. Biswas. Influence of pineal gland on spermatogenesis of toad (Bufo melanostictus). Hormone Res. 19: 200–204, 1984.
 176. Cheung, P. W., and C. McCormack. Failure of pinealectomy or melatonin to alter circadian activity rhythm of the rat. Am. J. Physiol. 242 (Regulatory Integrative Comp. Physiol. 13): R261–R264, 1982.
 177. Chiba, Y., and K. Tomioka. Insect circadian activity with special reference to the localization of the pacemaker. Zool. Sci. 4: 945–954, 1987.
 178. Chippendale, G. M., and S. Kikukawa. Effect of daylength and temperature on the larval diapause of the sunflower moth, Homoeosoma electellum. J. Insect Physiol. 29: 643–649, 1983.
 179. Christensen, N. D., and R. D. Lewis. The circadian locomotor rhythm of Hemideina thoracica (Orthoptera; Stenopelmatidae): the circadian clock as a population of interacting oscillators. Physiol. Entomol. 7: 1–13, 1982.
 180. Christensen, N. D., R. D. Lewis, and P. H. Gander. Properties of a feedback model for the circadian clock of Hemidiena thoracica (Orthoptera; Stenopelmatidae). Biol. Cybern. 51: 87–92, 1984.
 181. Claret, J. Mise en evidence du role photorécepteur du cerveau dans l'induction de la diapause chez Pieris brassicae (Lepidoptera). Ann. Endocrinol. 27: 311–320, 1966.
 182. Claret, J. Recherche du centre photorécepteur lors de l'induction de la diapause chez Pieris brassicae. C. R. Acad. Sci. III 262: 1464–1465, 1966.
 183. Claret, J. Le doimaine de photosensibilité du parasite Pimpla instigator F. (Hymenoptere Ichneumonidae) lors de Pentrée et de la levee photopériodiques de la diapause. C. R. Acad. Sci. III 276: 3163–3166, 1973.
 184. Claret, J. Modification du signal photopériodique par la cuticule de l'hote pour un endoparasite. C. R. Seances Soc. Biol. Fil. 176: 834–838, 1982.
 185. Claret, J. Vitamine A et induction photoperiodique ou thermoperiodique de la diapause chez Pieris brassicae (Lepidoptera). C. R. Acad. Sci. III 308: 347–352, 1989.
 186. Clarke, J. D., and G. J. Coleman. Persistent meal‐associated rhythms in SCN‐lesioned rats. Physiol. Behav. 36: 105–113, 1986.
 187. Coleman, G. J., S. Harper, J. D. Clarke, and S. Armstrong. Evidence for a separate meal‐associated oscillator in the rat. Physiol. Behav. 29: 107–115, 1982.
 188. Coleman, G. J., H. M. O'Reilly, and S. M. Armstrong. Food‐deprivation‐induced phase shifts in Sminthopsis macroura froggatti. J. Biol. Rhythms 4: 49–60, 1989.
 189. Collin, J.‐P., and A. Oksche. Structural and functional relationships in the nonmammalian pineal organ. In: The Pineal Gland. Anatomy and Biochemistry, edited by R. J. Reiter. Boca Raton, FL: CRC, 1981, vol. 1, p. 27–67.
 190. Collin, J.‐P., P. Voisin, J. Falcon, J.‐P. Faure, P. Brisson, and J.‐R. Defaye. Pineal transducers in the course of evolution: molecular organization, rhythmic metabolic activity and role. Arch. Histol. Cytol. 52: 441–449, 1989.
 191. Colwell, C. S. Light and serotonin interact in affecting the circadian system of Aplysia. J. Comp. Physiol. [A] 167: 841–845, 1990.
 192. Colwell, C. S., R. G. Foster, and M. Menaker. NMDA receptor antagonists block the effects of light on circadian behavior in the mouse. Brain Res. 554: 105–110, 1991.
 193. Colwell, C. S., S.B.S. Khalsa, and G. D. Block. Cellular mechanisms of entrainment. Chronobiol. Int. 3: 163–179, 1992.
 194. Colwell, C. S., S.B.S. Khalsa, and G. D. Block. FMRFamide modulates the action of phase shifting agents on the ocular circadian pacemakers of Aplysia and Bulla. J. Comp. Physiol. [A] 170: 211–215, 1992.
 195. Colwell, C. S., and T. L. Page. A circadian rhythm in neural activity can be recorded from the central nervous system of the cockroach. J. Comp. Physiol. [A] 166: 643–649, 1990.
 196. Coombs, C. W., and G. E. Woodroffe. The effect of temperature upon the longevity, fecundity and circannual development of Anthrenus sarnicus Mroczkowski (Coleoptera: Dermestidae). J. Stored Prod. Res. 19: 111–115, 1983.
 197. Copenhaver, P. F., and J. W. Truman. Control of neurosecretion in the moth Manduca sexta: physiological regulation of the eclosion hormone cells. J. Comp. Physiol. [A] 158: 445–455, 1986.
 198. Corrent, G., and A. Eskin. Transmitter‐like action of serotonin in phase shifting a rhythm from the Aplysia eye. Am. J. Physiol. 242 (Regulatory Integrative Comp. Physiol. 13): R333–R338, 1982.
 199. Corrent, G., D. J. McAdoo, and A. Eskin. Serotonin phase shifts the circadian rhythm from the Aplysia eye. Science 202: 977–979, 1978.
 200. Crews, D., and N. Greenberg. Function and causation of social signals in lizards. Am. Zool. 21: 273–294, 1981.
 201. Crews, D., V. Hingorani, and R. J. Nelson. Role of the pineal gland in the control of annual reproductive behavioral and physiological cycles in the red‐sided garter snake (Thamnophis sirtalis parietalis). J. Biol. Rhythms 3: 293–302, 1988.
 202. Crowley, M., and J. Bovet. Social synchronization of circadian rhythms in deer mice (Peromyscus maniculatus). Behav. Ecol. Sociobiol. 7: 99–105, 1980.
 203. Cuellar, H. S. Continuance of circannual reproductive refractoriness in pinealectomized whiptails, Cnemidophorus uniparens. J. Exp. Zool. 206: 207–214, 1978.
 204. Cuellar, H. S., and O. Cuellar. Evidence for endogenous rhythmicity in the reproductive cycle of the parthenogenetic lizard Cnemidophorus uniparens (Reptilia: Teiidae). Copeia 1977: 554–557, 1977.
 205. Cymborowski, B. Investigations on the neurohormonal factors controlling circadian rhythm of locomotor activity in the house cricket (Acheta domesticus L.). I. The role of the brain and the subesophageal ganglion. Zool. Pol. 20: 103–126, 1970.
 206. Cymborowski, B. Control of the circadian rhythm of locomotor activity in the house cricket. J. Insect Physiol. 19: 1423–1440, 1973.
 207. Cymborowski, B. Transplantation of circadian pacemaker in the house cricket, Acheta domesticus L. J. Interdiscipl. Cycle Res. 12: 133–140, 1981.
 208. Cymborowski, B., and A. Dutkowski. Circadian changes in protein synthesis in the neurosecretory cells of the central nervous system of Acheta domesticus. J. Insect Physiol. 16: 341–348, 1970.
 209. Cymborowski, B., M. Muszynska‐Pytel, P. Porcheron, and P. Cassier. Haemolymph ecdysteroid titres controlled by a circadian clock mechanism in larvae of the wax moth, Galleria mellonella. J. Insect Physiol. 37: 35–40, 1991.
 210. Daan, S., D. Damassa, C. S. Pittendrigh, and E. R. Smith. An effect of castration and testosterone replacement on a circadian pacemaker in mice (Mus musculus). Proc. Natl. Acad. Sci. U.S.A. 72: 3744–3747, 1975.
 211. Danilevskii, A. S. The photoperiodic reaction of insects in conditions of artificial light. Dokl. Akad. Nauk SSSR 60: 481–484, 1948.
 212. Danilevskii, A. S. Photoperiodism and Seasonal Development of Insects. London: Oliver & Boyd, 1965.
 213. Danks, H. V. Insect dormancy: an ecological perspective. Ottawa: Biological Survey of Canada, Monograph series 1, 1987.
 214. Dark, J., T. S. Kilduff, H. C. Heller, P. Licht, and I. Zucker. Suprachiasmatic nuclei influence hibernation rhythms of golden‐mantled ground squirrels. Brain Res. 509: 111–118, 1990.
 215. Dark, J., G. E. Pickard, and I. Zucker. Persistence of circannual rhythms in ground squirrels with lesions of the suprachiasmatic nuclei. Brain Res. 332: 201–207, 1985.
 216. Darrow, J. M., F. C. Davis, J. A. Elliott, M. H. Stetson, F. W. Turek, and M. Menaker. Influence of photoperiod on reproductive development in the golden hamster. Biol. Reprod. 22: 443–450, 1980.
 217. Darrow, J. M., and B. D. Goldman. Circadian regulation of pineal melatonin and reproduction in the Djungarian hamster. J. Biol. Rhythms 1: 39–53, 1986.
 218. Davis, F. C. Ontogeny of circadian rhythms. In: Handbook of Behavioral Neurobiology. Biological Rhythms, edited by J. Aschoff. New York: Plenum, 1981, vol. 4, p. 257–274.
 219. Davis, F. C., J. M. Darrow, and M. Menaker. Sex differences in the circadian control of hamster wheel‐running activity. Am. J. Physiol. 244 (Regulatory Integrative Comp. Physiol. 15): R93–R105, 1983.
 220. Davis, F. C., and R. A. Gorski. Development of hamster circadian rhythms: I. Within‐litter synchrony of mother and pup activity rhythms at weaning. Biol. Reprod. 33: 353–362, 1985.
 221. Davis, F. C., and R. A. Gorski. Development of hamster circadian rhythms: role of the maternal suprachiasmatic nucleus. J. Comp. Physiol. [A] 162: 601–610, 1988.
 222. Davis, F. C., and J. Mannion. Entrainment of hamster pup circadian rhythms by prenatal melatonin injections to the mother. Am. J. Physiol. 255 (Regulatory Integrative Comp. Physiol. 26): R439–R448, 1988.
 223. Davis, F. C., S. Stice, and M. Menaker. Activity and reproductive state in the hamster: independent control by social stimuli and a circadian pacemaker. Physiol. Behav. 40: 583–590, 1987.
 224. Davis, K. B., C. A. Goudie, B. A. Simco, R. MacGregor III, and N. C. Parker. Environmental regulation and influence of the eyes and pineal gland on the gonadal cycle and spawning in channel catfish (Ictalurus punctatus). Physiol. Zool. 59: 717–724, 1986.
 225. Day, J. R., and M. H. Taylor. Environmental control of the annual gonadal cycle of Fundulus heteroclitus L.: the pineal organ and eyes. J. Exp. Zool. 227: 453–458, 1983.
 226. De Coursey, P. J., and J. Buggy. Circadian rhythmicity after neural transplant to hamster third ventricle: specificity of suprachiasmatic nuclei. Brain Res. 500: 263–275, 1989.
 227. Deguchi, T. Ontogenesis of a biological clock for serotonin: acetyl coenzyme A N‐acetyltransferase in pineal gland of rat. Proc. Natl. Acad. Sci. U.S.A. 72: 2814–2818, 1975.
 228. Deguchi, T. Ontogenesis of circadian rhythm of melatonin synthesis in pineal gland of rat. J. Neural Transm. Suppl. 13: 115–128, 1978.
 229. Deguchi, T. A circadian oscillator in cultured cells of chicken pineal gland. Nature 282: 94–96, 1979.
 230. Deguchi, T. Rhodopsin‐like photosensitivity of isolated chicken pineal gland. Nature 290: 702–704, 1981.
 231. Delahunty, G., C. Schreck, J. Specker, J. Olcese, M. J. Vodicnik, and V. de Vlaming. The effects of light reception on circulating estrogen levels in female goldfish, Carassius auratus: importance of retinal pathways versus the pineal. Gen. Comp. Endocrinol. 38: 148–152, 1979.
 232. Delgado, M. J., P. Gutierrez, and M. Alonso‐Debate. Effects of daily melatonin injections on the photoperiodic gonadal response of the female frog Rana ridibunda. Comp. Biochem. Physiol. [A] 76: 389–392, 1983.
 233. Denlinger, D. L. Hormonal control of diapause. In: Comprehensive Insect Physiology, Biochemistry and Pharmacology, edited by G. A. Kerkut and L. I. Gilbert. New York: Pergamon, 1985, vol. 8, p. 354–412.
 234. de Vlaming, V. L. Effects of pinealectomy on gonadal activity in the cyprinid teleost, Notemigonous crysoleucas. Gen. Comp. Endocrinol. 26: 36–49, 1975.
 235. de Vlaming, V. L., M. Sage, and C. B. Charlton. The effects of melatonin treatment on gonosomatic index in the teleost, Fundulus similis and the tree frog, Hyla cinerea. Gen. Comp. Endocrinol. 22: 433–439, 1974.
 236. Devries, M. J., S. A. Ferreira, and J. D. Glass. Evidence that short photoperiod‐induced gonadal regression in the Mongolian gerbil is mediated by the action of melatonin in the medial hypothalamus. Brain Res. 494: 241–246, 1989.
 237. Devries, M. J., and J. H. Meijer. Aspartate injections into the suprachiasmatic region of the Syrian hamster do not mimic the effects of light on the circadian activity rhythm. Neurosci. Lett. 127: 215–218, 1991.
 238. de Wilde, J. Perception of the photoperiod by the Colorado potato beetle (Leptinotarsa decemlineata Say). Proc. Tenth Int. Congr. Entomol. 2: 213–218, 1956.
 239. de Wilde, J., and J. A. de Boer. Humoral and nervous pathways in photoperiodic induction of diapause in Leptinotarsa decemlineata. J. Insect Physiol. 15: 661–675, 1969.
 240. de Wilde, J., C. S. Duintjer, and L. Mook. Physiology of diapause in the adult Colorado beetle (Leptinotarsa decemlineata Say)—I. The photoperiod as a controlling factor. J. Insect Physiol. 3: 75–85, 1959.
 241. Dickson, R. C. Factors governing the induction of diapause in the oriental fruit moth. Ann. Entomol. Soc. Am. 42: 511–537, 1949.
 242. Dittami, J., and E. Gwinner. Circannual variations in plasma luteinizing hormone levels in castrated male European starlings (Sturnus vulgaris). J. Biol. Rhythms 2: 221–226, 1987.
 243. Dodt, E., and E. Heerd. Mode of action of pineal nerve fibers in frogs. J. Neurophysiol. 25: 405–429, 1962.
 244. Doncarlos, L. L., and J. A. Finkelstein. Hypothalamo‐spinal projections in the golden hamster. Brain Res. Bull. 18: 709–714, 1987.
 245. Donham, R. S., and F. E. Wilson. Photorefractoriness in pinealectomized Harris sparrows. Condor 72: 101–102, 1970.
 246. Dowell, S. F., and G. R. Lynch. Duration of the melatonin pulse in the hypothalamus controls testicular function in pinealectomized mice (Peromyscus leucopus). Biol. Reprod. 36: 1095–1101, 1987.
 247. Dubocovich, M. L. Characterization of a retinal melatonin receptor. J. Pharmacol. Exp. Ther. 234: 395–401, 1985.
 248. Dubocovich, M. L. Pharmacology and function of melatonin receptors. FASEB J. 2: 2765–2773, 1988.
 249. Dubocovich, M. L. Role of melatonin in the retina. In: Progress in Retinal Research, edited by N. Osborne and G. Chadir. New York: Pergamon, 1988, vol. 8, p. 129–151.
 250. Dumortier, 15. Photoreception in the circadian rhythm of stridulatory activily in Ephippiger (Ins., Orthoptera): likely existence of two photoreceptive systems. J. Comp. Physiol. 77: 80–112, 1972.
 251. Dumortier, D., and J. Brunnarius. Physiologie des invertebres—existence d'une composante circadienne dans l'induction thermopériodique de la diapause chez Pieris brassicae L. C. R. Acad. Sci. III 285: 361–364, 1977.
 252. Dumortier, B., and J. Brunnarius. Diet‐dependent switch from circadian to hourglass‐like operation of an insect photoperiodic clock. J. Biol. Rhythms 4: 481–490, 1989.
 253. Duncan, M. J., M. J. Banister, and S. M. Reppert. Developmental appearance of light–dark entrainment in the rat. Brain Res. 369: 326–330, 1986.
 254. Duncan, M. J., and R. A. Mead. Autoradiographic localization of binding sites for 2‐[125I]iodomelatonin in the pars tuberalis of the western spotted skunk (Spilogale putorius latifrons). Brain Res. 569: 152–155, 1992.
 255. Duncan, M. J., J. S. Takahashi, and M. L. Dubocovich. Characteristics and autoradiographic localization of 2‐[125I]iodomelatonin binding sites in Djungarian hamster brain. Endocrinology 125: 1011–1018, 1989.
 256. Dushay, M. S., M. Rosbash, and J. Hall. The disconnected visual system mutations in Drosophila melanogaster drastically disrupt circadian rhythms. J. Biol. Rhythms 4: 1–28, 1989.
 257. Duston, J., and N. Bromage. Photoperiodic mechanisms and rhythms of reproduction in the female rainbow trout. Fish Physiol. Biochem. 2: 35–51, 1986.
 258. Duston, J., and N. Bromage. Constant photoperiod regimes and the entrainment of the annual cycle of reproduction in the female rainbow trout (Salmo gairdneri). Gen. Comp. Endocrinol. 65: 373–384, 1987.
 259. Duston, J., and N. Bromage. The entrainment and gating of the endogenous circannual rhythm of reproduction in the female rainbow trout (Salmo gairdneri). J. Comp. Physiol. [A] 164: 259–268, 1988.
 260. Duston, J., and N. Bromage. Circannual rhythms of gonadal maturation in female rainbow trout (Oncorhynchus mykiss). J. Biol. Rhythms 6: 49–53, 1991.
 261. Earnest, D. J., M. Iadarola, H. H. Yeh, and J. A. Olschowka. Photic regulation of c‐fos expression in neural components governing the entrainment of circadian rhythms. Exp. Neurol. 109: 353–361, 1990.
 262. Earnest, D. J., and C. D. Sladek. Circadian rhythms of vasopressin release from individual rat suprachiasmatic explants in vitro. Brain Res. 382: 129–133, 1986.
 263. Earnest, D. J., C. D. Sladek, D. M. Gash, and S. J. Wiegand. Specificity of circadian function in transplants of the fetal suprachiasmatic nucleus. J. Neurosci. 9: 2671–2677, 1989.
 264. Earnest, D. J., and F. W. Turek. Neurochemical basis for the photic control of circadian rhythms and seasonal reproductive cycles: role for acetylcholine. Proc. Natl. Acad. Sci. U.S.A. 82: 4277–4281, 1985.
 265. Ebihara, S., and H. Kawamura. The role of the pineal organ and the suprachiasmatic nucleus in the control of circadian locomotor rhythms in the Java sparrow, Padda oryzivora. J. Comp. Physiol. 141: 207–214, 1981.
 266. Ebihara, S., K. Uchiyama, and I. Oshima. Circadian organization in the pigeon, Columba livia: the role of the pineal organ and the eye. J. Comp. Physiol. [A] 154: 59–69, 1984.
 267. Ebisawa, T., S. Karne, M. R. Lerner, and S. M. Reppert. Expression cloning of high‐affinity melatonin receptors from Xenopus dermal melanophores. Proc. Natl. Acad. Sci. U.S.A. 91: 6133–6137, 1994.
 268. Ebling, F.J.P., and D. L. Foster. Pineal melatonin rhythms and the timing of puberty in mammals. Experientia 45: 946–954, 1989.
 269. Ebling, F. J. P., E. S. Maywood, K. Staley, T. Humby, D. C. Hancock, C. M. Waters, G. I. Evan, and M. H. Hastings. The role of N‐methyl‐d‐aspartate‐type glutamatergic neurotransmission in the photic induction of immediate‐early gene expression in the suprachiasmatic nuclei of the Syrian hamster. J. Neuroendocrinal. 3: 641–652, 1991.
 270. Ebling, F.J.P., R. I. Wood, J. M. Suttie, T. E. Adel, and D. L. Foster. Prenatal photoperiod influences neonatal prolactin secretion in the sheep. Endocrinology 125: 384–391, 1989.
 271. Edgar, D. M., and W. C. Dement. Regularly scheduled voluntary exercise synchronizes the mouse circadian clock. Am. J. Physiol. 261 (Regulatory Integrative Comp. Physiol. 32): R928–R933, 1991.
 272. Edgar, D. M., C. E. Martin, and W. C. Dement. Activity feedback to the mammalian circadian pacemaker: influence on observed measures of rhythm period length. J. Biol. Rhythms 6: 185–199, 1991.
 273. Elliott, J. A. Circadian rhythms and photoperiodic time measurement in mammals. Federation Proc. 35: 2339–2346, 1976.
 274. Elliott, J. A., Bartness, T. J., and B. D. Goldman. Effect of melatonin infusion duration and frequency on gonad, lipid, and body mass in pinealectomized male Siberian hamsters. J. Biol. Rhythms 4: 439–455, 1989.
 275. Elliott, J. A., and B. D. Goldman. Seasonal reproduction photoperiodism and biological clocks. In: Neuroendocrinology of Reproduction: Physiology and Behavior, edited by N. T. Adler. New York: Plenum, 1981, p. 377–423.
 276. Elliott, J. A., and B. D. Goldman. Reception of photoperiodic information by fetal Siberian hamsters: role of the mother's pineal gland. J. Exp. Zool. 252: 237–244, 1989.
 277. Elliott, J. A., M. H. Stetson, and M. Menaker. Regulation of testis function in golden hamsters: a circadian clock measures photoperiodic time. Science 178: 771–773, 1972.
 278. Ellis, G. B., R. E. McKlveen, and F. W. Turek. Dark pulses affect the circadian rhythm of activity in hamsters kept in constant light. Am J. Physiol. 242 (Regulatory Integrative Comp. Physiol. 13): R44–R50, 1982.
 279. Ellis, G. B., and F. W. Turek. Testosterone and photoperiod interact to regulate locomotor activity in male hamsters. Horm. Behav. 17: 66–75, 1983.
 280. Engelmann, W., and H. W. Honegger. Tagesperiodische Schlüpfryhthmik liner augenlosen Drosophila melanogaster‐Mutante. Naturwissenschaften 53: 588, 1966.
 281. Eriksson, L. O. Die Jahresperiodik augen‐ und pinealorganloser Bachsaiblinge Salvelinus fontinalis Mitchell. Aquilo Ser. Zool. 13: 8–12, 1972.
 282. Eriksson, L. O. Tagesperiodik geblendeter Bachsaiblinge. Naturwissenschaften 59: 219–220, 1972.
 283. Erkert, H. G., and U. Schardt. Social entrainment of circadian activity rhythms in common marmosets, Callithrix j. jacchus (Primates). Ethology 87: 189–202, 1991.
 284. Eskes, G. A., M. Wilkinson, W. H. Moger, and B. Rusak. Periventricular and suprachiasmatic lesion effects on photoperiodic responses of the hamster hypophyseal–gonadal axis. Biol. Reprod. 30: 1073–1081, 1984.
 285. Eskin, A. Properties of the Aplysia visual system: in vitro entrainment of the circadian rhythm and centrifugal regulation of the eye. Z. Vergleich. Physiol. 74: 353–371, 1971.
 286. Eskin, A. Phase shifting a circadian rhythm in the eye of Aplysia by high potassium pulses. J. Comp. Physiol. 80: 353–376, 1972.
 287. Eskin, A. Neurophysiological mechanisms involved in photoentrainment of the circadian rhythm from the Aplysia eye. J. Neurobiol. 8: 273–299, 1977.
 288. Eskin, A., and E. Harcombe. Eye of Navanax: optic activity, circadian rhythm and morphology. Comp. Biochem. Physiol. A 57: 443–449, 1977.
 289. Eskin, A., J. Takahashi, M. Zatz, and G. D. Block. Cyclic GMP mimics the effects of light on a circadian pacemaker in the eye of Aplysia. J. Neurosci. 4: 2466–2471, 1984.
 290. Falcon, J., J. B. Marmillon, B. Claustrat, and J.‐P. Collin. Regulation of melatonin secretion in a photoreceptive pineal organ: an in vitro study in the pike, J. Neurosci. 9: 1943–1950, 1989.
 291. Falcon, J., and H. Meissl. The photosensory function of the pineal organ of the pike (Esox lucius L.). Correlation between structure and function. J. Comp. Physiol. 144: 127–137, 1981.
 292. Farner, D. S., R. S. Donham, R. A. Lewis, P. W. Mattocks, Jr., T. R. Darden, and J. P. Smith. The circadian component in the photoperiodic mechanism of the house sparrow, Passer domesticus. Physiol. Zool. 50: 247–268, 1977.
 293. Farner, D. S., R. S. Donham, K. S. Matt, P. W. Mattocks, M. C. Moore, and J. C. Wingfield. The nature of photorefractoriness. In: Avian Endocrinology: Environmental and Ecological Perspectives, edited by S. Ishii, S. I. Mikami, and M. Wada. Berlin: Springer‐Verlag, 1983, p. 149–166.
 294. Farner, D. S., and B. K. Follett. Reproductive periodicity in birds. In: Hormones and Evolution, edited by E.J.W. Barrington. New York: Academic, 1979, p. 829–872.
 295. Farner, D. S., and E. Gwinner. Photoperiodicity, circannual and reproductive cycles. In: Avian Endocrinology, edited by A. Epple and M. H. Stetson. New York: Academic, 1980, p. 331–366.
 296. Farner, D. S., and J. C. Wingfield. Reproductive endocrinology of birds. Annu. Rev. Physiol. 42: 457–472, 1980.
 297. Farrar, G. M., and J. R. Clarke. Effect of chemical sympathectomy and pinealectomy upon gonads of voles (Microtus agrestis) exposed to short photoperiod. Neuroendocrinology 22: 134–143, 1976.
 298. Fenwick, J. C. Demonstration and effect of melatonin in fish. Gen. Comp. Endocrinol. 14: 86–97, 1970.
 299. Ferenz, H. J. Photoperiodic and hormonal control of reproduction in male beetles, Pterostichus nigrita. J. Insect Physiol. 21: 331–341, 1975.
 300. Ferrell, B. R. Photoperiodism in the lizard Anolis carolinensis. J. Exp. Zool. 232: 19–27, 1984.
 301. Finkelstein, J. S., F. R. Baum, and C. S. Campbell. Entrainment of the female hamster to reversed photoperiod: role of the pineal. Physiol. Behav. 21: 105–111, 1978.
 302. Firth, B. T., and D. J. Kennaway. Thermoperiod and photoperiod interact to affect the phase of the plasma melatonin rhythm in the lizard, Tiliqua rugosa. Neurosci. Lett. 106: 125–130, 1989.
 303. Firth, B. T., D. J. Kennaway, and I. Belan. Thermoperiodic influences on plasma melatonin rhythms in the lizard Tiliqua rugosa: effect of thermophase duration. Neurosci. Lett. 121: 139–142, 1991.
 304. Fisher, M. W., P. F. Fennessy, and P. D. Johnstone. The timing of melatonin treatment affects the seasonal onset of ovarian activity, coat growth and live weight in young red deer hinds. Anim. Reprod. Sci. 23: 49–59, 1990.
 305. Fitzgerald, K. M., and I. Zucker. Circadian organization of the estrous cycle of the golden hamster. Proc. Natl. Acad. Sci. U.S.A. 73: 2923–2927, 1976.
 306. Flannery, J. G., and S. K. Fisher. Circadian disc shedding in Xenopus retina in vitro. Invest. Ophthalmol. Vis. Sci. 25: 229–232, 1984.
 307. Fleissner, G. Entrainment of the scorpion's circadian rhythm via the median eyes. J. Comp. Physiol. 118: 93–99, 1977.
 308. Fleissner, G. Scorpion lateral eyes: extremely sensitive receptors of zeitgeber stimuli. J. Comp. Physiol. 118: 101–108, 1977.
 309. Fleissner, G. Isolation of an insect circadian clock. J. Comp. Physiol. 149: 311–316, 1982.
 310. Fleissner, G. Efferent neurosecretory fibres as pathways for circadian clock signals in the scorpion. Naturwissenschaften 70: 366–367, 1983.
 311. Fleissner, G. Die innere Uhr und der Lichtsinn von Skorpionen und Kafern. Naturwissenschaften 73: 78–88, 1986.
 312. Fleissner, G., and G. Fleissner. Neurobiology of a circadian clock in the visual system of scorpions. In: Neurobiology of Arachnids, edited by F. G. Barth. Berlin: Springer‐Verlag, 1985, p. 251–375.
 313. Foà, A. The role of the pineal and the retinae in the expression of circadian locomotor rhythmicity in the ruin lizard Podarcis sicula. J. Comp. Physiol. [A] 169: 201–207, 1991.
 314. Follett, B. K. Birds. In: Marshall's Physiology of Reproduction. Reproductive Cycles of Vertebrates, edited by G. E. Lamming. New York: Churchill Livingstone, 1984, vol. 1, p. 283–350.
 315. Follett, B. K., R. G. Foster, and T. J. Nicholls. Photoperiodism in birds. In: Photoperiodism, Melatonin, and the Pineal, edited by D. Evered and S. Clark. London: Pitman, 1985, p. 93–103.
 316. Follett, B. K., and A. S. Pearce‐Kelly. Photoperiodic induction in quail as a function of the period of the light‐dark cycle: implications for models of time measurement. J. Biol. Rhythms 6: 331–341, 1991.
 317. Follett, B. K., and P. J. Sharp. Circadian rhythmicity in photoperiodically induced gonadotrophin release and gonadal growth in the quail. Nature 223: 968–971, 1969.
 318. Forsberg, M., J. A. Fougner, P. O. Hofmo, and E. J. Einarsson. Effect of melatonin implants on reproduction in the male silver fox (Vulpes vulpes). J. Reprod. Fertil. 88: 383–388, 1990.
 319. Foster, D. L., F.J.P. Ebling, L. E. Claypool, and C.J.I. Woodfill. Cessation of long day melatonin rhythms time puberty in a short day breeder. Endocrinology 123: 1636–1641, 1988.
 320. Foster, R. G., and B. K. Follett. The involvement of a rhodopsin‐like photopigment in the photoperiodic response of the Japanese quail. J. Comp. Physiol. [A] 157: 519–528, 1985.
 321. Foster, R. G., B. K. Follett, and J. N. Lythgoe. Rhodopsin‐like sensitivity of extraretinal photoreceptors mediating the photoperiodic response in quail. Nature 313: 50–52, 1985.
 322. Foster, R. G., J. M. Garcia‐Fernandez, I. Provencio, and W. J. de Grip. Opsin localization and chromophore retinoids identified within the basal brain of the lizard Anolis carolinensis. J. Comp. Physiol. [A] 172: 33–45, 1993.
 323. Foster, R. G., I. Provencio, D. Hudson, S. Fiske, W. de Grip, and M. Menaker. Circadian photoreception in the retinally degenerate mouse (rd/rd). J. Comp. Physiol. [A] 169: 39–50, 1991.
 324. Foster, R. G., A. M. Timmers, J. J. Schalken, and W. J. de Grip. A comparison of some photoreceptor characteristics in the pineal and retina. J. Comp. Physiol. [A] 165: 565–572, 1989.
 325. Fowler, P. A., and P. A. Racey. Effect of melatonin administration and long day‐length on endocrine cycles in the hedgehog, Erinaceus europaeus. J. Pineal Res. 8: 67–78, 1990.
 326. Fraile, B., R. Paniagua, and M. C. Rodriguez. Long day photoperiods and temperature of 20° induce spermatogenesis in blinded and non‐blinded marbled newts during the period of testicular quiescence. Biol. Reprod. 39: 649–655, 1988.
 327. Fraile, B., R. Paniagua, M. C. Rodriguez, and F. J. Saez. Effect of photoperiod on testicular function in blinded and non‐blinded marbled newts, Triturus marmoratus. J. Morphol. 200: 151–162, 1989.
 328. Francois‐Bellan, A. M., P. Kachidian, G. Dusticier, M. C. Tonon, H. Vaudry, and O. Bosler. GABA neurons in the rat suprachiasmatic nucleus: involvement in chemospecific synaptic circuitry and evidence for GAD‐peptide colocalization. J. Neurocytol. 19: 937–947, 1990.
 329. Frank, K. D., and W. F. Zimmerman. Action spectra for phase shifts of a circadian rhythm in Drosophila. Science 163: 688–689, 1969.
 330. Fuchs, J. L. Effects of pinealectomy and subsequent melatonin implants on activity rhythms in the house finch (Carpodacus mexicanus). J. Comp. Physiol. 153: 413–419, 1983.
 331. Fuentes‐Pardo, B., and V. Inclan‐Rubio. Caudal photoreceptors synchronize the circadian rhythms in crayfish—I. Synchronization of the ERG and locomotor circadian rhythms. Comp. Biochem. Physiol. A 86: 523–527, 1987.
 332. Fujishita, M., and H. Ishizaki. Circadian clock and prothoracicotropic hormone secretion in relation to the larval‐larval ecdysis rhythm of the saturnid Samia cynthia ricini. J. Insect Physiol. 27: 122–128, 1981.
 333. Gander, P. H., and R. D. Lewis. The circadian locomotor activity rhythm of Hemideina thoracicia (Orthoptera): feedback model for the underlying clock oscillation. Int. J. Chronobiol. 6: 263–280, 1979.
 334. Garg, S. K. Role of pineal and eyes in the regulation of ovarian activity and vitellogenin levels in the catfish exposed to continuous light or continuous dark. J. Pineal Res. 5: 1–12, 1988.
 335. Garg, S. K. Effect of pinealectomy, eye enucleation, and melatonin treatment on ovarian activity and vitellogenin levels in the catfish exposed to short photoperiod or long photoperiod. J. Pineal Res. 7: 91–104, 1989.
 336. Garg, S. K., and B. I. Sundararaj. Role of pineal in the regulation of some aspects of circadian rhythmicity in the catfish, Heteropneustes fossilis (Bloch). Chronobiologia 13: 1–11, 1986.
 337. Garner, W. W., and H. A. Allard. Effect of the relative length of the day and night and other factors of the environment on growth and reproduction in plants. J. Agricult. Res. 18: 553–606, 1920.
 338. Gaston, S. The influence of the pineal organ on the circadian activity rhythm in birds. In: Biochronometry, edited by M. Menaker. Washington, DC: National Academy of Sciences, 1971, p. 541–548.
 339. Gaston, S., and M. Menaker. Pineal function: the biological clock in the sparrow? Science 160: 1125–1127, 1968.
 340. Geispitz, K. F. The mechanism of acceptance of light stimuli in the photoperiodic reaction of Lepidoptera larvae. Zool. Zh. 36: 548–560, 1957.
 341. Geldiay, S. The location of photoperiodic receptors and the activity of the neurosecretory cells of Anacridium aegyptium L. under different photoperiods. Sci. Rep. Pac. Sci. Ege Univ. 89, 1969.
 342. Geldiay, S. Photoperiodic control of neurosecretory cells in the brain of the Egyptian grasshopper, Anacridium aegyptium L. Gen. Comp. Physiol. 14: 35–42, 1970.
 343. Geldiay, S., and S. Karacali. Rhabdome‐bearing cells within the corpus cardiacum of Melanogryllus desertus (Orthoptera, Gryllidae). Gen. Comp. Endocrinol. 51: 239–245, 1983.
 344. Gelman, D. B., and D. K. Hayes. Cyclic 3', 5'‐AMP phosphodiesterase activity in head extracts of the five larval instars of the European corn borer, Ostrina nubilalis (Hubner), and in extracts of brains of the fifth instar. Comp. Biochem. Physiol. [C] 61: 249–253, 1978.
 345. Gelman, D. B., B. S. Thyagaraja, T. J. Kelly, E. P. Masler, R. A. Bell, and A. Borkovec. Prothoracicotropic hormone levels in brains of the European corn borer, Ostrinia nubilalis: diapause vs the non‐diapause state. J. Insect Physiol. 38: 383–395, 1992.
 346. Gerkema, M. P., G. A. Groos, and S. Daan. Differential elimination of circadian and ultradian rhythmicity by hypothalamic lesions in the common vole, Microtus arvalis. J. Biol. Rhythms 5: 81–95, 1990.
 347. Gern, W. A., and S. S. Greenhouse. Examination of in vitro melatonin secretion from superfused trout (Salmo gairdneri) pineal organs maintained under diel illumination or continuous darkness. Gen. Comp. Endocrinol. 71: 163–174, 1988.
 348. Gern, W. A., J. M. Nervina, and S. S. Greenhouse. Pineal involvement in seasonality of reproduction. In: Hormones and Reproduction in Fishes, Amphibians, and Reptiles, edited by D. O. Norris and R. E. Jones. New York: Plenum, 1987, p. 433–460.
 349. Geusz, M. E., and G. D. Block. The retinal cells generating the circadian small spikes in the Bulla optic nerve. J. Biol. Rhythms 7: 255–268, 1992.
 350. Geusz, M. E., R. G. Foster, M. D. Lawrence, and G. D. Block. Opsin‐like immunoreactivity in the putative pacemaker neurons in the Bulla eye. Soc. Neurosci. Abstr. 17: 1240, 1991.
 351. Geusz, M. E., and T. L. Page. The circadian rhythm and photosensitivity of small impulses of the Bulla eye. J. Comp. Physiol. 166: 795–801, 1990.
 352. Geusz, M. E., and T. L. Page. An opsin‐based photopigment mediates phase shifts of the Bulla circadian pacemaker. J. Comp. Physiol. [A] 168: 565–570, 1991.
 353. Giebultowicz, J. M., R. A. Bell, and R. B. Imberski. Circadian rhythm of sperm movement in the male reproductive tract of the gypsy moth Lymantria dispar. J. Insect Physiol. 34: 527–532, 1988.
 354. Giebultowicz, J. M., J. G. Riemann, A. K. Raina, and R. L. Ridgway. Circadian system controlling release of sperm in the insect testes. Science 245: 1098–1100, 1989.
 355. Gillette, M. U. The suprachiasmatic nuclei: circadian phase‐shifts induced at the time of hypothalamic slice preparation are preserved in vitro. Brain Res. 379: 176–181, 1986.
 356. Gillette, M. U. SCN electrophysiology in vitro: rhythmic activity and endogenous clock properties. In: Suprachiasmatic Nucleus. The Mind's Clock, edited by D. C. Klein, R. Y. Moore, and S. M. Reppert. New York: Oxford Univ. Press, 1991, p. 125–143.
 357. Gillette, M. U., and R. A. Prosser. Circadian rhythm of the rat suprachiasmatic brain slice is rapidly reset by daytime application of cAMP analogs. Brain Res. 474: 348–352, 1988.
 358. Girardie, A., and S. Granier. Système endocrine et physiologie de la diapause imaginale chez le criquet Egyptien Anacridium aegyptium. J. Insect Physiol. 19: 2341–2358, 1973.
 359. Glass, J. D., and J. K. Lauber. Sites and action spectra for encephalic photoreception in the Japanese quail. Am. J. Physiol. 240 (Regulatory Integrative Comp. Physiol. 11): R220–R228, 1981.
 360. Glass, J. D., and G. R. Lynch. Melatonin: identification of sites of antigonadal action in mouse brain. Science 214: 821–823, 1981.
 361. Glass, J. D., and G. R. Lynch. The effect of superficial pinealectomy on reproduction and brown fat in the adult white‐footed mouse, Peromyscus leucopus. J. Comp. Physiol. 144: 145–152, 1981.
 362. Glass, J. D., and G. R. Lynch. Evidence for a brain site of melatonin action in the white‐footed mouse, Peromyscus leucopus. Neuroendocrinology 34: 1–6, 1982.
 363. Gnagey, A. L., and D. L. Denlinger. Photoperiodic induction of pupal diapause in the flesh fly, Sarcophaga crassipalpis: embryonic sensitivity. J. Comp. Physiol. [B] 154: 91–96, 1984.
 364. Goldman, B. D. Parameters of the circadian rhythm of pineal melatonin secretion affecting reproductive responses in Siberian hamsters. Steroids 56: 218–225, 1991.
 365. Goldman, B. D., J. M. Darrow, and L. Yogev. Effects of timed melatonin infusions on reproductive development in the Djungarian hamster (Phodopus sungorus). Endocrinology 114: 2074–2083, 1984.
 366. Goldman, B. D., and J. A. Elliott. Photoperiodism and seasonality in hamsters: role of the pineal gland. In: Processing of Environmental Information in Vertebrates, edited by M. H. Stetson. New York: Springer‐Verlag, 1988, p. 203–218.
 367. Goldman, B. D., V. Hall, C. Hollister, P. Roychoudhury, L. Tamarkin, and W. Westrom. Effects of melatonin on the reproductive system in intact and pinealectomized male hamsters maintained under various photoperiods. Endocrinology 104: 82–88, 1979.
 368. Goodman, R. L. Neuroendocrine mechanisms mediating the photoperiodic control of reproductive function in sheep. In: Processing of Environmental Information in Vertebrates, edited by M. H. Stetson. New York: Springer‐Verlag, 1988, p. 179–202.
 369. Gordon, S. A., and G. A. Brown. Observations on spectral sensitivities for the phasing of circadian temperature rhythms in Perognathus penicillatus. In: Biochronometry, edited by M. Menaker. Washington, DC: National Academy of Sciences, 1971, p. 363–371.
 370. Gordon, W. H., J. L. Larimer, and T. L. Page. Circumesophageal interneurons required for reflexive and circadian locomotor behaviors in the crayfish. J. Comp. Physiol. 116: 227–238, 1977.
 371. Goryshin, N. I., and G. F. Tyshchenko. The accumulation of photoperiod information in the cabbage moth Barathra brassicae L. (Lepidoptera, Noctuidae) during diapause induction. Entomol. Obozr. 52: 249–255, 1973.
 372. Goss, R. J. Photoperiodic control of antler cycles in deer I. Phase shift and frequency changes. J. Exp. Zool. 170: 311–324, 1969.
 373. Goss, R. J. Photoperiodic control of antler cycles in deer III. Decreasing versus increasing day lengths. J. Exp. Zool. 197: 307–312, 1976.
 374. Grocock, C. A. Effect of different photoperiods on testicular weight changes in the vole, Microtus agrestis. J. Reprod. Fertil. 62: 25–32, 1981.
 375. Grocock, C. A., and J. R. Clarke. Photoperiodic control of testis activity in the vole, Microtus agrestis. J. Reprod. Fertil. 39: 337–347, 1974.
 376. Groos, G., and J. Hendriks. Circadian rhythm in electrical discharge of rat suprachiasmatic neurones recorded in vitro. Neurosci. Lett. 34: 283–288, 1982.
 377. Guldner, F. H. Synapses of optic nerve afferents in the rat suprachiasmatic nucleus. I. Identification, qualitative description, development and distribution. Cell Tissue Res. 194: 17–35, 1978.
 378. Guyomarc'h, C., and J. C. Guyomarc'h. Sexual development and free‐running period in quail kept in constant darkness. Gen. Comp. Endocrinol. 86: 103–110, 1992.
 379. Gwinner, E. Periodicity of a circadian rhythm in birds by species‐specific song cycles (Aves, Fringillidae: Carduelis spinus, Serinus serinus). Experientia 22: 765–766, 1966.
 380. Gwinner, E. Testosterone induces “splitting” of circadian locomotor activity rhythms in birds. Science 185: 72–74, 1974.
 381. Gwinner, E. Effects of season and external testosterone on the freerunning circadian activity rhythm of European starlings (Sturnus vulgaris). J. Comp. Physiol. 103: 315–328, 1975.
 382. Gwinner, E. Photoperiodic synchronization of circannual rhythms in the European starling (Sturnus vulgaris). Naturwissenschaften 64: 44, 1977.
 383. Gwinner, E. Effects of pinealectomy on circadian locomotor activity rhythms in European starlings, Sturnus vulgaris. J. Comp. Physiol. 126: 123–129, 1978.
 384. Gwinner, E. Circannual rhythms: their dependence on the circadian system. In: Biological Clocks in Seasonal Reproductive Cycles, edited by B. K. Follett and D. E. Follett. Bristol: Wright, 1981, p. 153–169.
 385. Gwinner, E. Circannual systems. In: Handbook of Behavioral Neurobiology. Biological Rhythms, edited by J. Aschoff. New York: Plenum, 1981, vol. 4, p. 381–389.
 386. Gwinner, E. Circannual Rhythms. Berlin: Springer‐Verlag, 1986.
 387. Gwinner, E. Photoperiod as a modifying and limiting factor in the expression of avian circannual rhythms. J. Biol. Rhythms 4: 237–250, 1989.
 388. Gwinner, E. Endogenous—exogenous interactions in circannual rhythms. In: Progress in Comparative Endocrinology, edited by A. Epple, C. G. Scanes, and M. H. Stetson. New York: Wiley‐Liss, 1990, p. 632–638.
 389. Gwinner, E., and I. Benzinger. Synchronization of a circadian rhythm in pinealectomized European starlings by daily injections of melatonin. J. Comp. Physiol. 127: 209–213, 1978.
 390. Gwinner, E., and J. Dittami. Pinealectomy affects the circannual testicular rhythm in European starlings (Sturnus vulgaris). J. Comp. Physiol. 136: 345–348, 1980.
 391. Gwinner, E., and J. Dittami. Pineal influences on circannual cycles in European starlings: effects through the circadian system? In: Vertebrate Circadian Systems, edited by J. Aschoff, S. Daan, and G. Groos. Berlin: Springer‐Verlag, 1982, p. 276–284.
 392. Gwinner, E., and J. Dittami. Endogenous reproductive rhythms in a tropical bird. Science 249: 906–908, 1990.
 393. Gwinner, E., J. P. Dittami, and H.J.A. Beldhuis. The seasonal development of photoperiodic responsiveness in an equatorial migrant, the garden warbler Sylvia borin. J. Comp. Physiol. [A] 162: 389–396, 1988.
 394. Gwinner, E., and L. Eriksson. Circadiane Rhythmik und photoperiodische Zeitmessung beim Star (Sturnus vulgaris). J. Ornithol. 118: 60–67, 1977.
 395. Gwinner, E., and W. Wiltschko. Endogenously controlled changes in migratory direction of the garden warbler, Sylvia borin. J. Comp. Physiol. 125: 267–273, 1978.
 396. Gwinner, E., J. Wozniak, and J. Dittami. The role of the pineal organ in the control of annual rhythms in birds. In: The Pineal Organ: Photobiology—Biochronometry—Endocrinology, edited by A. Oksche and P. Pévet. Amsterdam: Elsevier, 1981, p. 99–121.
 397. Hairston, N. G., Jr., and E. J. Olds. Partial photoperiodic control of diapause in three populations of the freshwater copepod Diaptomus sanguineus. Biol. Bull. 171: 135–142, 1986.
 398. Hakim, H., A. P. Debernardo, and R. Silver. Orcadian locomotor rhythms, but not photoperiodic responses, survive surgical isolation of the SCN in hamsters. J. Biol. Rhythms 6: 97–113, 1991.
 399. Halberg, F., F. Halberg, and A. Giese. Circannual biochemical and gonadal index rhythms of marine invertebrates. In: Chronobiology, edited by L. E. Schewig, F. Halberg, and J. E. Pauly. Tokyo: Igaku Shoin, 1974, p. 703–708.
 400. Halberg, F., F. Halberg, R. B. Sothern, J. S. Pearse, V. B. Pearse, K. Shankaraiah, and A. C. Giese. Consistent synchronization and circaseptennian (about‐7‐yearly) modulation of circannual gonadal index rhythm of three marine invertebrates. Prog. Clin. Biol. Res. 227A: 225–238, 1987.
 401. Haldar, C., and M. Ghosh. Annual pineal and testicular cycle in the Indian jungle bush quail, Perdicula asiatica, with reference to the effect of pinealectomy. Gen. Comp. Endocrinol. 77: 150–157, 1990.
 402. Haldar, C., and R. Pandey. Effect of pinealectomy on annual testicular cycle of Indian chequered water snake, Natrix piscator. Gen. Comp. Endocrinol. 76: 214–222, 1989.
 403. Haldar, C., and J. P. Thapliyal. Effect of pinealectomy on the annual testicular cycle of Calotes versicolor. Gen. Comp. Endocrinol. 32: 395–399, 1977.
 404. Haldar, C., and J. P. Thapliyal. Response of reptilian gonad to melatonin. Neuroendocrinology 33: 328–332, 1981.
 405. Hall, J. C., and M. Rosbash. Genetic and molecular analysis of biological rhythms. J. Biol. Rhythms 2: 153–178, 1987.
 406. Hamasaki, D. I., and D. J. Eder. Adaptive radiation of the pineal system. In: Handbook of Sensory Physiology, edited by F. Crescitelli. New York: Springer‐Verlag, 1977, p. 497–548.
 407. Hamner, K. C., and A. Takimoto. Circadian rhythms and plant photoperiodism. Am. Nat. 98: 295–322, 1964.
 408. Hamner, W. M. Diurnal rhythm and photoperiodism in testicular recrudescence of the house finch. Science 142: 1294–1295, 1963.
 409. Hamner, W. M. Circadian control of photoperiodism in the house finch demonstrated by interrupted‐night experiments. Nature 203: 1400–1401, 1964.
 410. Hamner, W. M., and R. J. Barfield. Ineffectiveness of pineal lesions on the testis cycle of a finch. Condor 72: 99–101, 1970.
 411. Hamner, W. M., and J. T. Enright. Relationships between photoperiodism and circadian rhythms of activity in the house finch. J. Exp. Biol. 46: 43–61, 1967.
 412. Handler, A. M., and R. J. Konopka. Transplantation of a circadian pacemaker in Drosophila. Nature 279: 236–238, 1979.
 413. Hanna, W.J.B., J. A. Horne, and G. H. Renninger. Circadian photoreceptor organs in Limulus. J. Comp. Physiol. [A] 162: 133–140, 1988.
 414. Hardie, J., A. D. Lees, and S. Young. Light transmission through the head capsule of an aphid, Megoura viciae. J. Insect Physiol. 27: 773–777, 1981.
 415. Harrington, M. E., D. M. Nance, and B. Rusak. Neuropeptide Y immunoreactivity in the hamster geniculo‐suprachiasmatic tract. Brain Res. Bull. 15: 465–472, 1985.
 416. Harrington, M. E., and B. Rusak. Lesions of the thalamic intergeniculate leaflet alter hamster circadian rhythms. J. Biol. Rhythms 1: 309–325, 1986.
 417. Harrington, M. E., and B. Rusak. Ablation of the geniculohypothalamic tract alters circadian activity rhythms of hamsters housed under constant light. Physiol. Behav. 42: 183–189, 1988.
 418. Harrison, P. C. Extraretinal photocontrol of reproductive responses of leghorn hens to photoperiods of different length and spectrum. Poultry Sci. 51: 2060–2064, 1972.
 419. Hartwig, H. G., and T. van Veen. Spectral characteristics of visible radiation penetrating into the brain and stimulating extraretinal photoreceptors. J. Comp. Physiol. 130: 277–282, 1979.
 420. Hasegawa, K., and I. Shimizu. In vivo and in vitro photoperiodic induction of diapause using isolated brain–subesophageal ganglion complexes of the silkworm, Bombyx mori. J. Insect Physiol. 33: 959–966, 1987.
 421. Hasegawa, K., and I. Shimizu. Occurrence of retinal and 3‐hydroxyretinal in a possible photoreceptor of the silkworm brain involved in photoperiodism. Experientia 44: 74–76, 1988.
 422. Hastings, J. W., B. Rusak, and Z. Boulos. Circadian rhythms: the physiology of biological timing. In: Neural and Integrative Animal Physiology, edited by C. L. Prosser. New York: Wiley‐Liss, 1991, p. 435–546.
 423. Hastings, M. H., A. P. Walker, J. B. Powers, J. Hutchison, E. A. Steel, and J. Herbert. Differential effects of photoperiodic history on the responses of gonadotrophins and prolactin to intermediate daylengths in the male Syrian hamster. J. Biol. Rhythms 4: 335–350, 1989.
 424. Hastings, M. H., A. P. Walker, A. C. Roberts, and J. Herbert. Intra‐hypothalamic melatonin blocks photoperiodic responsiveness in the male Syrian hamster. Neuroscience 24: 987–991, 1988.
 425. Hau, M., and E. Gwinner. Circadian entrainment by feeding cycles in house sparrows, Passer domesticus. J. Comp. Physiol. [A] 170: 403–409, 1992.
 426. Hauser, R. Untersuchungen zu voltinismus und flügelpolymorphismus beim wasserlaüfer Gerris lacustris (Hemiptera, Gerridae). Rev. Suisse Zool. 89: 903–917, 1982.
 427. Hazel, W. M., and D. A. West. Environmental control of pupal colour in swallowtail butterflies (Lepidoptera: Papilioninae): Battus philenor (L.) and Papilio polyxenes Fabr. Ecol. Entomol. 4: 393–400, 1979.
 428. Hegdekar, B. M. Epicuticular wax secretion in diapause and non‐diapause pupae of the bertha armyworm. Ann. Entomol. Soc. Am. 72: 13–15, 1979.
 429. Heinrichs, S., and G. Fleissner. Neuronal components of the circadian clock in the scorpion, Androctonus australis: central origin of the efferent neurosecretory elements projecting to the median eyes. Cell Tissue Res. 250: 277–285, 1987.
 430. Helfrich, C. Role of the optic lobes in the regulation of the locomotor activity rhythm of Drosophila melanogaster: behavioral analysis of neural mutants. J. Neurogenet. 3: 321–343, 1986.
 431. Helfrich, C., B. Cymborowski, and W. Engelmann. Circadian activity rhythm of the house fly continues after optic tract severance and lobectomy. Chronobiol. Int. 2: 19–32, 1985.
 432. Helfrich, C., and W. Engelmann. Circadian locomotor activity in Drosophila melanogaster mutants “sine oculis” and “small optic lobes.” Physiol. Entomol. 8: 257–272, 1983.
 433. Hendrickson, A. E., N. Wagoner, and W. M. Cowan. An autoradiographic and electron microscope study of retino‐hypothalamic connections. Z. Zellforsch. 135: 1–26, 1972.
 434. Herbert, J., P. M. Stacey, and D. H. Thorpe. Recurrent breeding seasons in pinealectomized or optic‐nerve‐sectioned ferrets. J. Endocrinol. 78: 389–397, 1978.
 435. Hillman, W. S. Endogenous circadian rhythms and the response of Lemna perpusilla to skeleton photoperiods. Am. Nat. 98: 323–328, 1964.
 436. Hillman, W. S. Non‐circadian photoperiodic timing in the aphid Megoura. Nature 242: 128–129, 1973.
 437. Hiroshige, T. Maternal phase control of fetal circadian oscillation during pregnancy. Jpn. J. Physiol. 36: 237–251, 1986.
 438. Hiroshige, T., K. Honma, and K. Watanabe. Possible zeitgebers for external entrainment of the circadian rhythm of plasma corticosterone in blind infantile rats. J. Physiol. (Lond.) 325: 507–519, 1982.
 439. Hiroshige, T., K. Honma, and K. Watanabe. Prenatal onset and maternal modification of the circadian rhythm of plasma corticosterone in blind infantile rats. J. Physiol. (Lond.) 325: 521–532, 1982.
 440. Hisano, S., M. Chikamori‐Aoyama, S. Katoh, M. Maegawa, and S. Daikoku. Immunohistochemical evidence of serotonergic regulation of vasoactive intestinal polypeptide (VIP) in the rat suprachiasmatic nucleus. Histochemistry 86: 573–578, 1987.
 441. Hochachka, P. W., and M. Guppy. Metabolic Arrest and the Control of Biological Time. Cambridge: Harvard Univ. Press, 1987.
 442. Hodkova, M. Nervous inhibition of corpora allata by photoperiod in Pyrrhocoris apterus. Nature 263: 521–523, 1976.
 443. Hoffman, R. A., and R. J. Reiter. Influence of compensatory mechanisms and the pineal gland on dark‐induced gonadal atrophy in male hamsters. Nature 203: 658–659, 1965.
 444. Hoffman, R. A., and R. J. Reiter. Pineal gland: influence on gonads of male hamsters. Science 148: 1609–1611, 1965.
 445. Hoffman, R. A., and R. J. Reiter. Responses of some endocrine organs of female hamsters to pinealectomy and light. Life Sci. 5: 1147–1151, 1966.
 446. Hoffmann, K. Experimental manipulation of the orientational clock in birds. Cold Spring Harbor Symp. Quant. Biol. 25: 379–387, 1960.
 447. Hoffmann, K. Synchronisation der circadianen Aktivitatsperiodik von Eidechsen durch Temperaturcyclen verschiedener Amplitude. Z. Vergl. Physiol. 58: 225–228, 1968.
 448. Hoffmann, K. Splitting of the circadian rhythm as a function of light intensity. In: Biochronometry, edited by M. Menaker. Washington, DC: National Academy of Sciences, 1971, p. 134–151.
 449. Hoffmann, K. The influence of photoperiod and melatonin on testis size, body weight, and pelage colour in the Djungarian hamster (Phodopus sungorus). J. Comp. Physiol. 85: 267–282, 1973.
 450. Hoffmann, K. Photoperiodic mechanism in hamsters: the participation of the pineal gland. In: Environmental Endocrinology, edited by I. Assenmacher and D. S. Farner. Berlin: Springer‐Verlag, 1978, p. 94–102.
 451. Hoffmann, K., H. Illnerova, and J. Vanecek. Change in duration of nighttime melatonin peak may be a signal driving photoperiodic responses in the Djungarian hamster (Phodopus sungorus). Neurosci. Lett. 67: 68–72, 1986.
 452. Homma, K., M. Ohta, and Y. Sakakibara. Photo‐inducible phase of the Japanese quail detected by direct stimulation to the brain. In: Biological Rhythms and Their Central Mechanisms, edited by M. Suda, O. Hayaishi, and H. Nakagawa. Amsterdam: Elsevier, 1979, p. 85–94.
 453. Homma, K., M. Ohta, and Y. Sakakibara. Surface and deep photoreceptors in photoperiodism in birds. In: Biological Rhythms in Birds, edited by Y. Tanake, K. Tanaka, and T. Ookawa. Berlin: Springer‐Verlag, 1980, p. 149–156.
 454. Homma, K., and Y. Sakakibara. Encephalic photoreceptors and their significance in photoperiodic control of sexual activity in Japanese quail. In: Biochronometry, edited by M. Menaker. Washington, DC: National Academy of Sciences, 1971, p. 333–341.
 455. Homma, K., W. O. Wilson, and T. D. Siopes. Eyes have a role in photoperiodic control of sexual activity of Coturnix. Science 178: 421–423, 1972.
 456. Hong, S. M., and M. H. Stetson. Detailed diurnal rhythm of sensitivity to melatonin injections in Turkish hamsters, Mesocricetus brandti. J. Pineal Res. 4: 69–78, 1987.
 457. Honma, K., S. Honma, and T. Hiroshige. Activity rhythms in the circadian domain appear in suprachiasmatic nuclei lesioned rats given methamphetamine. Physiol. Behav. 40: 767–774, 1987.
 458. Honma, K., S. Honma, T. Shirakawa, and T. Hiroshige. Phase setting of circadian locomotor rhythm of infant rats. Am. J. Physiol. 252 (Regulatory Integrative Comp. Physiol. 23): R256–R261, 1987.
 459. Honma, K., C. von Goetz, and J. Aschoff. Effects of restricted daily feeding on freerunning circadian rhythms in rats. Physiol. Behav. 30: 905–913, 1983.
 460. Honma, S., K. I. Honma, T. Hagasaka, and T. Hiroshige. The ventromedial hypothalamic nucleus is not essential for the prefeeding corticosterone peak in rats under restricted daily feeding. Physiol. Behav. 39: 211–215, 1986.
 461. Honma, S., K. Honma, and T. Hiroshige. Rhythms in behaviors, body temperature and plasma corticosterone in SCN lesioned rats given methamphetamine. Physiol. Behav. 44: 247–255, 1988.
 462. Honma, S., K. Honma, T. Shirakawa, and T. Hiroshige. Maternal phase setting of fetal circadian oscillation underlying the plasma corticosterone rhythm in rats. Endocrinology 114: 1791–1796, 1984.
 463. Hontela, A., and R. E. Peter. Effects of pinealectomy, blinding, and sexual condition on serum gonadotropin levels in the goldfish. Gen. Comp. Endocrinol. 40: 168–179, 1980.
 464. Home, J. A., and G. H. Renninger. Circadian photoreceptor organs in Limulus. J. Comp. Physiol [A] 162: 127–132, 1988.
 465. Horton, T. H. Growth and reproductive development of male Microtus montanus is affected by the prenatal photoperiod. Biol. Reprod. 31: 499–504, 1984.
 466. Horton, T. H. Cross‐fostering of voles demonstrates in utero effect of photoperiod. Biol. Reprod. 33: 934–939, 1985.
 467. Horton, T. H., S. L. Ray, and M. H. Stetson. Maternal transfer of photoperiodic information in Siberian hamsters. III. Melatonin injections program postnatal reproductive development expressed in constant light. Biol. Reprod. 41: 34–39, 1989.
 468. Horton, T. H., S. A. Stachecki, and M. H. Stetson. Maternal transfer of photoperiodic information in Siberian hamsters. IV. Peripubertal reproductive development in the absence of maternal photoperiodic signals during gestation. Biol. Reprod. 42: 441–449, 1990.
 469. Horton, T. H., and M. H. Stetson. Maternal programming of the fetal brain dictates the response of juvenile Siberian hamsters to photoperiod: dissecting the information transfer system. J. Exp. Zool. Suppl. 4: 200–202, 1990.
 470. Horwath, K.L.M., and J. G. Duman. Further studies on the involvement of the circadian system in photoperiodic control of the antifreeze protein production in the beetle Dendroides canadensis. J. Insect Physiol. 30: 947–955, 1984.
 471. Horwath, K.L.M., and J. G. Duman. Thermoperiodic involvement in antifreeze protein production in the cold hardy beetle Dendroides canadensis: implications for photoperiodic time measurement. J. Insect Physiol. 32: 799–806, 1986.
 472. Huber, F. Neural integration. In: The Physiology of Insecta, edited by M. Rockstein. New York: Academic, 1965, vol. 2, p. 333–406.
 473. Hudson, D., and M. Lickey. Internal desychronization between two identified circadian oscillators in Aplysia. Brain Res. 183: 481–485, 1980.
 474. Hudson, R., and H. Distel. The pattern of behavior of rabbit pups in the nest. Behaviour 79: 255–271, 1982.
 475. Hyde, F., A. Wilkens, and L. Rensing. The effects of temperature on the circadian rhythms of flashing and glow in Gonyaulax polyedra: are the two rhythms controlled by two oscillators? J. Biol. Rhythms 7: 115–124, 1992.
 476. Hyde, L. L., and H. Underwood. Daily melatonin infusions entrain the locomotor activity of pinealectomized lizards. Physiol. Behav. 58: 943–951, 1995.
 477. Ibata, Y., Y. Takahashi, H. Okamura, F. Kawakami, H. Terubayashi, T. Kubo, and N. Yanaihara. Vasoactive intestinal peptide (VIP)‐like immunoreactive neurons located in the rat suprachiasmatic nucleus receive a direct retinal projection. Neurosci. Lett. 97: 1–5, 1989.
 478. Iigo, M., H. Kezsuka, K. Aida, and I. Hanyu. Circadian rhythms of melatonin secretion from superfused goldfish (Carassius auratus) pineal glands in vitro. Gen. Comp. Endocrinol. 83: 152–158, 1991.
 479. Illnerová, H. The suprachiasmatic nucleus and rhythmic pineal melatonin production. In: Suprachiasmatic Nucleus. The Mind's Clock, edited by D. C. Klein, R. Y. Moore, and S. M. Reppert. New York: Oxford Univ. Press, 1991, p. 197–216.
 480. Illnerová, H., J. Vaněček, and K. Hoffmann. Different mechanisms of phase delays and phase advances of the circadian rhythm in rat pineal N‐aceicyltransferase activity. J. Biol. Rhythms 4: 187–200, 1989.
 481. Immelmann, K. Ecological aspects of periodic reproduction. In: Avian Biology, edited by D. S. Farner and J. R. King. New York: Academic, 1971, vol. 1, p. 342–389.
 482. Inouye, S. T. Restricted daily feeding does not entrain circadian rhythms of the suprachiasmatic nucleus in the rat. Brain Res. 232: 194–199, 1982.
 483. Inouye, S. T. Ventromedial hypothalamic lesions eliminate anticipatory activities of restricted daily feeding schedules in the rat. Brain Res. 250: 183–187, 1982.
 484. Inouye, S. T. Does the ventromedial hypothalamic nucleus contain a self‐sustained circadian oscillator associated with periodic feeding? Brain Res. 279: 53–63, 1983.
 485. Inouye, S. T., and H. Kawamura. Persistence of circadian rhythmicity in a mammalian hypothalamic “island” containing the suprachiasmatic nucleus. Proc. Natl. Acad. Sci. U.S.A. 76: 5962–5966, 1979.
 486. Inouye, S. T., and H. Kawamura. Characteristics of a circadian pacemaker in the suprachiasmatic nucleus. J. Comp. Physiol. 146: 153–160, 1982.
 487. Ishisaki, H., A. Mizoguchi, and M. Fujishita. Circadian clock control of hormone secretion in Samia cynthia ricini. In: Photoperiodic Regulation of Insect and Molluscan Hormones, edited by R. Porter and G. Collins. London: Pitman, 1984, p. 221–232.
 488. Jacklet, J. W. Circadian rhythm of optic nerve impulses recorded in darkness from isolated eye of Aplysia. Science 164: 562–563, 1969.
 489. Jacklet, J. W. A circadian rhythm in the optic nerve impulses from an isolated eye in darkness. In: Biochronometry, edited by M. Menaker. Washington, DC: National Academy of Sciences, 1971, p. 351–362.
 490. Jacklet, J. W. The effects of constant light and light pulses on the circadian rhythm in the eye of Aplysia. J. Comp. Physiol. 90: 33–45, 1974.
 491. Jacklet, J. W. Light sensitivity of the rhinophores and eyes of Aplysia. J. Comp. Physiol. [A] 136: 257–262, 1980.
 492. Jacklet, J. W. Photoresponsiveness of Aplysia eye is modulated by the ocular circadian pacemaker and serotonin. Biol. Bull. 180: 284–294, 1991.
 493. Jacklet, J. W., and W. Colquhoun. Ultrastructure of photoreceptors and circadian pacemaker neurons in the eye of a gastropod, Bulla. J. Neurocytol. 12: 373–396, 1983.
 494. Jacklet, J. W., M. Klose, and M. Goldberg. FMRF‐amide‐like immunoreactive efferent fibers and FMRF‐amide suppression of pacemaker neurons in eyes of Bulla. J. Neurobiol. 18: 433–449, 1987.
 495. Jackson, G. L., H. Jansen, and C. Kao. Continuous exposure of Suffolk ewes to an equatorial photoperiod disrupts expression of the annual breeding season. Biol. Reprod. 42: 63–73, 1990.
 496. Janik, D. S., and M. Menaker. Circadian locomotor rhythms in the desert iguana. I. The role of the eyes and the pineal. J. Comp. Physiol. [A] 166: 803–810, 1990.
 497. Janik, D. S., G. E. Pickard, and M. Menaker. Circadian locomotor rhythms in the desert iguana. II. Effects of electrolytic lesions to the hypothalamus. J. Comp. Physiol. [A] 166: 811–816, 1990.
 498. Jegla, T. C., and T. L. Poulson. Circannual rhythms—I. Reproduction in the cave crayfish, Orconectes pellucidus inermis. Comp. Biochem. Physiol. 33: 347–355, 1970.
 499. Jilge, B., H. Hornicke, and H. Stahle. Circadian rhythms of rabbits during restrictive feeding. Am. J. Physiol. 253 (Regulatory Integrative Comp. Physiol. 24): R46–R54, 1987.
 500. John, T. M., J. C. George, and R. J. Etches. Influence of subcutaneous melatonin implantation on gonadal development and on plasma levels of luteinizing hormone, testosterone, estradiol, and corticosterone in the pigeon. J. Pineal Res. 3: 169–179, 1986.
 501. Johnson, R. F., R. Y. Moore, and L. P. Morin. Lateral geniculate lesions alter circadian activity rhythms in the hamster. Brain Res. Bull. 22: 411–422, 1989.
 502. Johnson, R. F., L. Smale, R. Y. Moore, and L. P. Morin. Lateral geniculate lesions block circadian phase‐shift responses to a benzodiazepine. Proc. Natl. Acad. Sci. U.S.A. 85: 5301–5304, 1988.
 503. Johnson, R. F., L. Smale, R. Y. Moore, and L. P. Morin. Paraventricular nucleus efferents mediating photoperiodism in male golden hamsters. Neurosci. Lett. 98: 85–90, 1989.
 504. Jordan, W. P., M. Lickey, and S. Hiaasen. Circadian organization in Aplysia: internal desynchronization and amplitude of locomotor rhythm. J. Comp. Physiol. [A] 156: 293–303, 1985.
 505. Joy, J. E., and N. Mrosovsky. Circannual cycles in golden‐mantled ground squirrels: lengthening of period by low temperatures in the spring phase. J. Comp. Physiol. 150: 233–238, 1983.
 506. Joy, J. E., and N. Mrosovsky. Synchronization of circannual cycles: a cold spring delays the cycles of thirteen‐lined ground squirrels. J. Comp. Physiol. [A] 156: 125–134, 1985.
 507. Joy, K. P., and A. K. Agha. Seasonal effects of pinealectomy on the ovary of the catfish Heteropneustes fossilis (Bloch) under normal photothermal conditions. J. Pineal Res. 7: 281–289, 1989.
 508. Joy, K. P., and A. K. Agha. Seasonal effects of administration of melatonin and 5‐methoxytryptophol on ovarian activity in the catfish Heteropneustes fossilis (Bloch). J. Pineal Res. 10: 65–70, 1991.
 509. Joy, K. P., and I. A. Khan. Pineal–gonadal relationship in the teleost Channa punctatus (Bloch): evidence for possible involvement of hypothalamic serotonergic system. J. Pineal Res. 11: 12–22, 1991.
 510. Karasek, M. Ultrastructure of the mammalian pineal gland: its comparative and functional aspects. In: Pineal Research Reviews, edited by R. J. Reiter. New York: Liss, 1983, vol. 1, p. 1–48.
 511. Karp, J. D., M. E. Dixon, and J. B. Powers. Photoperiod history, melatonin, and reproductive responses of male Syrian hamsters. J. Pineal Res. 8: 137–152, 1990.
 512. Karsch, F. J., B. Malpaux, N. L. Wayne, and J. A. Robinson. Characteristics of the melatonin signal that provide the photoperiodic code for timing seasonal reproduction in the ewe. Reprod. Nutr. Dev. 28: 459–472, 1988.
 513. Karsch, F. J., C.J.I. Woodfill, B. Malpaux, J. E. Robinson, and N. L. Wayne. Melatonin and mammalian photoperiodism: synchronization of annual reproductive cycles. In: Suprachiasmatic Nucleus. The Mind's Clock, edited by D. C. Klein, R. Y. Moore, and S. M. Reppert. New York: Oxford Univ. Press, 1991, p. 217–232.
 514. Kasai, M., and Y. Chiba. Effects of optic lobe ablation on circadian activity in the mosquito, Culex pipiens pallens. Physiol. Entomol. 12: 59–65, 1987.
 515. Kass, L., and R. B. Barlow, Jr. Efferent neurotransmission of circadian rhythms in Limulus lateral eye. J. Heurosci. 4: 908–917, 1984.
 516. Kass, L., and R. B. Barlow, Jr. A circadian clock in the Limulus brain transmits synchronous efferent signals to all eyes. Vis. Neurosci. 9: 493–504, 1992.
 517. Kavaliers, M. Pineal involvement in the control of circadian rhythmicity in the lake chub, Couesius plumbeus. J. Exp. Zool. 209: 33–40, 1979.
 518. Kavaliers, M. Circadian locomotor activity rhythms of the burbot, Lota lota: seasonal differences in period length and the effect of pinealectomy. J. Comp. Physiol. 136: 215–218, 1980.
 519. Kavaliers, M. Retinal and extraretinal entrainment action spectra for the activity rhythms of the lake chub, Couesius plumbeus. Behav. Neural Biol. 30: 56–67, 1980.
 520. Kavaliers, M. Social groupings and circadian activity of the killifish, Fundulus heteroclitus. Biol. Bull. 158: 69–76, 1980.
 521. Kavaliers, M. Circadian and ultradian activity rhythms of a freshwater gastropod, Helisoma trivolis: the effects of social factors and eye removal. Behav. Neural Biol. 32: 350–363, 1981.
 522. Kavaliers, M. Circadian organization in white suckers Catostomus commersoni: the role of the pineal organ. Comp. Biochem. Physiol. A 68: 127–129, 1981.
 523. Keefe, D. L., D. J. Earnest, D. Nelson, J. S. Takahashi, and F. W. Turek. A cholinergic antagonist, mecamylamine, blocks the phase‐shifting effects of light on the circadian rhythm of locomotor activity in the golden hamster. Brain Res. 403: 308–312, 1987.
 524. Kenny, N.A.P., and D. S. Saunders. Adult locomotor rhythmicity as “hands” of the maternal photoperiodic clock regulating larval diapause in the blowfly, Calliphora vicina. J. Biol. Rhythms 6: 217–233, 1991.
 525. Kezuka, H., K. Aida, and I. Hanyu. Melatonin secretion from goldfish pineal gland in organ culture. Gen. Comp. Endocrinol. 75: 217–221, 1989.
 526. Khalsa, S.B.S., and G. D. Block. Calcium channels mediate phase shifts of the Bulla circadian pacemaker. J. Comp. Physiol. [A] 164: 195–206, 1988.
 527. Khalsa, S.B.S., and G. D. Block. Calcium in phase control of the Bulla circadian pacemaker. Brain Res. 506: 40–45, 1990.
 528. Kimura, T., and S. Masaki. Brachypterism and seasonal adapation in Orgyia thyellina Butler (Lepidoptera, Lymantriidae). Kontyu 45: 97–106, 1977.
 529. Kitay, J. I., and M. D. Altschule. The Pineal Gland. Cambridge, MA: Harvard Univ. Press, 1954.
 530. Kittrell, E.M.W. The suprachiasmatic nucleus and temperature rhythms. In: Suprachiasmatic Nucleus. The Mind's Clock, edited by D. C. Klein, R. Y. Moore, and S. M. Reppert. New York: Oxford Univ. Press, 1991, p. 233–245.
 531. Klein, D. C. Evidence for placental transfer of 3H‐acetyl‐melatonin. Nature 237: 117, 1972.
 532. Kleinknecht, S. Lack of social entrainment of free‐running circadian activity rhythms in the Australian sugar glider (Petaurus breviceps: Marsupialia). Behav. Ecol. Sociobiol. 16: 189–193, 1985.
 533. Klemm, E., and H. Ninnemann. Detailed action spectrum for the delay shift in pupae emergence of Drosophila pseudoobscura. Photochem. Photobiol. 24: 369–371, 1976.
 534. Koehler, W. K., and G. Fleissner. Internal desynchronization of bilaterally organized circadian oscillators in the visual system of insects. Nature 274: 708–710, 1978.
 535. Kogure, M. The influence of light and temperature on certain characters of the silkworm, Bombyx mori. J. Dept. Agricult. Kyushu Univ. 4: 1–93, 1933.
 536. Koltermann, R. Periodicity in the activity and learning performance of the honey bee. In: Experimental Analysis of Insect Behavior, edited by L. Barton Brown. New York: Springer‐Verlag, 1974, p. 218–227.
 537. Konishi, H., M. Ohta, and K. Homma. Important role of the eyes controlling the locomotor rhythm in quail. J. Interdiscipl. Cycle Res. 16: 217–226, 1985.
 538. Kono, Y. Daily changes of neurosecretory type‐II cell structure of Pieris larvae entrained by short and long days. J. Insect Physiol. 21: 249–264, 1975.
 539. Kono, Y., M. Kobayashi, and J. Claret. A putative photoreceptor‐organelle in insect brain glial cell. Appl. Entomol. Zool. 18: 116–121, 1983.
 540. Konopka, R., and S. Benzer. Clock mutants of Drosophila melanogaster. Proc. Nat. Acad. Sci. U.S.A. 68: 2112–2116, 1971.
 541. Korf, H.‐W., and M. Møller. The innervation of the mammalian pineal gland with special reference to central pinealopetal projections. In: Pineal Research Reviews, edited by R. J. Reiter. New York: Liss, 1984, vol. 2, p. 41–86.
 542. Kornhauser, J. M., D. E. Nelson, K. E. Mayo, and J. S. Takahashi. Photic and circadian regulation of c‐fos gene expression in the hamster suprachiasmatic nucleus. Neuron 5: 127–134, 1990.
 543. Koumenis, C., and A. Eskin. The hunt for mechanisms of circadian timing in the eye of Aplysia. Chronobiol. Int. 9: 201–221, 1992.
 544. Koveos, D. S., and M. E. Tzanakakis. Effect of hydration, photoperiod and temperature on diapause termination in eggs of Petrobia (Tetranychina) harti (Acari: Tetranychidae). Exp. Appl. Acarol. 11: 111–123, 1991.
 545. Krause, D. N., and M. L. Dubocovich. Regulatory sites in the melatonin system of mammals. Trends Neurosci. 13: 464–470, 1990.
 546. Krause, D. N., and M. L. Dubocovich. Melatonin receptors. Annu. Rev. Pharmacol. Toxicol. 31: 549–568, 1991.
 547. Krieger, D. T. Ventromedial hypothalamic lesions abolish food‐shifted circadian adrenal and temperature rhythmicity. Endocrinology 106: 649–654, 1980.
 548. Krieger, D. T., H. Hauser, and L. C. Krey. Suprachiasmatic nuclear lesions do not abolish food‐shifted circadian adrenal and temperature rhythmicity. Science 197: 398–399, 1977.
 549. Krieger, M. S., J. T. Morrell, and D. W. Pfaff. Autoradiographic localization of estradiol‐concentrating cells in the female hamster brain. Neuroendocrinology 22: 193–205, 1976.
 550. Kumar, V., and P. D. Tewary. Photoperiodic regulation of the gonadal recrudescence in common Indian rosefinch: dependence on circadian rhythms. J. Exp. Zool. 223: 37–40, 1982.
 551. Kupwade, V. A., and S. K. Saidapur. Effect of melatonin on oocyte growth and recruitment, hypophyseal gonadotrophs, and oviduct of the frog Rana cyanophlyctis maintained under natural photoperiod during the prebreeding phase. Gen. Comp. Endocrinol. 54: 284–292, 1986.
 552. Kurumiya, S., and H. Kawamura. Damped oscillation of the lateral hypothalamic multineuronal activity synchronized to daily feeding schedules in rats with suprachiasmatic nucleus lesions. J. Biol. Rhythms 6: 115–127, 1991.
 553. Laitinen, J. T., E. Castren, O. Vakkuri, and J. M. Saavedra. Diurnal rhythm of melatonin binding in the rat suprachiasmatic nucleus. Endocrinology 124: 1585–1587, 1989.
 554. Laitinen, J. T., G. Flugge, and J. M. Saavedra. Characterization of melatonin receptors in the rat area postrema: modulation of affinity with cations and guanine nucleotides. Neuroendocrinology 51: 619–624, 1990.
 555. Laitinen, J. T., and J. M. Saavedra. Characterization of melatonin receptors in the rat suprachiasmatic nuclei: modulation of affinity with cations and guanine nucleotides. Endocrinology 126: 2110–2115, 1990.
 556. Larimer, J., and J.T.F. Smith. Circadian rhythm of retinal sensitivity in crayfish: modulation by the cerebral and optic ganglia. J. Comp. Physiol. 136: 313–326, 1980.
 557. Laubier‐Bonichon, A., and K. Mangold. La maturation sexuelle chez les males d'Octopus vulgaris (Cephalopoda: Octopoda), en relation avec le reflexe photo‐sexuel. Marine Biol. 29: 45–52, 1975.
 558. Lee, T. M., N. Spears, C. R. Tuthill, and I. Zucker. Maternal melatonin treatment influences rates of neonatal development of meadow vole pups. Biol. Reprod. 40: 495–502, 1989.
 559. Lee, T. M., and I. Zucker. Suprachiasmatic nucleus and photic entrainment of circannual rhythms in ground squirrels. J. Biol. Rhythms 6: 315–330, 1991.
 560. Lees, A. D. Environmental factors controlling the evocation and termination of diapause in the fruit tree red spider mite Metatetranycus ulmi Koch (Acarina: tetranychidae). Ann. Appl. Biol. 40: 449–486, 1953.
 561. Lees, A. D. The significance of the light and dark phases in the photoperiodic control of diapause in Metatetranychus ulmi Koch. Ann. Appl. Biol. 41: 487–497, 1953.
 562. Lees, A. D. The Physiology of Diapause in Arthropods. Cambridge; Cambridge Univ. Press, 1955.
 563. Lees, A. D. On the structure of the egg shell in the mite Petrobia latens Muller (Acarina: Tetranychidae). J. Insect Physiol. 6: 146–151, 1961.
 564. Lees, A. D. The location of the photoperiodic receptors in the aphid Megoura viciae Buckton. J. Exp. Biol. 41: 119–133, 1964.
 565. Lees, A. D. Is there a circadian component in the Megoura photoperiodic clock? In: Circadian Clocks, edited by J. Aschoff. Amsterdam: North‐Holland, 1965, p. 351–356.
 566. Lees, A. D. The control of polymorphism in aphids. Adv. Insect Physiol. 3: 207–277, 1966.
 567. Lees, A. D. Insect Clocks and Timers. London: Imperial College of Science and Technology, 1970, Inaugural Lecture.
 568. Lees, A. D. The relevance of action spectra in the study of insect photoperiodism. In: Biochronometry, edited by M. Menaker. Washington, DC: National Academy of Sciences, 1971, p. 372–380.
 569. Lees, A. D. Photoperiodic time measurement in the aphid Megoura viciae. J. Insect Physiol. 19: 2279–2316, 1973.
 570. Lees, A. D. Action spectra for the photoperiodic control of polymorphism in the aphid Megoura viciae. J. Insect Physiol. 27: 761–771, 1981.
 571. Lees, A. D. Dual photoperiodic timers controlling sex and female morph determination in the pea aphi Acyrthosiphon pisum. J. Insect Physiol. 36: 585–591, 1990.
 572. Legan, S. J., and F. J. Karsch. A daily signal for the LH surge in the rat. Endocrinology 96: 57–62, 1975.
 573. Lehman, M. N., E. L. Bittman, and S. W. Newman. Role of the hypothalamic paraventricular nucleus in neuroendocrine responses to daylength in the golden hamster. Brain Res. 308: 25–32, 1984.
 574. Lehman, M. N., R. Silver, W. R. Gladstone, R. M. Kahn, M. Gibson, and E. L. Bittman. Circadian rhythmicity restored by neural transplant. Immunocytochemical characterization of the graft and its integration with the host brain. J. Neurosci. 7: 1626–1638, 1987.
 575. Lerner, A. B., J. D. Case, Y. Takahashi, T. H. Lee, and W. Mori. Isolation of melatonin, the pineal gland factor that lightens melanocytes. J. Am. Chem. Soc. 80: 2587, 1958.
 576. Levey, I. L. Effects of pinealectomy and melatonin injections at different seasons on ovarian activity in the lizard, Anolis carolinensis. J. Exp. Zool. 185: 169–174, 1973.
 577. Lewis, R. D., and D. S. Saunders. A damped circadian oscillator model of an insect photoperiodic clock. I. Description of the model based on a feedback control system. J. Theor. Biol. 128: 47–59, 1987.
 578. Licht, P. Environmental physiology of reptilian breeding cycles: role of temperature. Gen. Comp. Endocrinol. 3 (Suppl.): 477–488, 1972.
 579. Licht, P. Reptiles. In: Marshall's Physiology of Reproduction. Reproductive Cycles of Vertebrates, edited by G. E. Lamming. New York: Churchill Livingstone, 1984, vol. 1, p. 206–282.
 580. Lickey, M., D. Hudson, and S. Hiaasen. Circadian organization in Aplysia: relations between locomotor rhythm and eye rhythms after cutting both, one, or neither optic nerves. J. Comp. Physiol. 153: 133–143, 1983.
 581. Lickey, M., and J. Wozniak. Circadian organization in Aplysia explored with red light, eye removal, and behavioral recording. J. Comp. Physiol. 131: 169–177, 1979.
 582. Lickey, M., J. Wozniak, G. Block, D. Hudson, and G. Augter. The consequences of eye removal for the circadian rhythm of behavioral activity in Aplysia. J. Comp. Physiol. 118: 121–143, 1977.
 583. Lickey, M. E., G. D. Block, D. J. Hudson, and J. T. Smith. Circadian oscillators and photoreceptors in the gastropod, Aplysia. Photochem. Photobiol. 23: 253–273, 1976.
 584. Lincoln, C., and C. E. Palm. Biology and ecology of the alfalfa snout beetle. Cornell Univ. Agricult. Exp. Station Memoirs 236: 1–44, 1941.
 585. Lincoln, G. A., E. A. Libre, and G. R. Merriam. Long‐term reproductive cycles in rams after pinealectomy or superior cervical ganglionectomy. J. Reprod. Fertil. 85: 687–704, 1989.
 586. Liou, S. Y., and H. E. Albers. Single unit response of neurons within the hamster suprachiasmatic nucleus to GABA and low chloride perfusate during the day and night. Brain Res. Bull. 25: 93–98, 1990.
 587. Liou, S. Y., and H. E. Albers. Single unit response of neurons within the hamster suprachiasmatic nucleus to neuropeptide. Y. Brain Res. Bull. 27: 825–828, 1991.
 588. Liou, S. Y., S. Shibata, H. E. Albers, and S. Ueki. Effects of GABA and anxiolytics on the single unit discharge of suprachiasmatic neurons in rat hypothalamic slices. Brain Res. Bull. 25: 103–107, 1990.
 589. Liou, S. Y., S. Shibata, K. Iwasaki, and S. Ueki. Optic nerve stimulation‐induced increase of release of 3H‐glutamate and 3H‐aspartate but not 3H‐GABA from the suprachiasmatic nucleus in slices of rat hypothalamus. Brain Res. Bull. 16: 527–531, 1986.
 590. Loher, W. Orcadian control of stridulation in the cricket, Teleogryllus commodus Walker. J. Comp. Physiol. 79: 173–190, 1972.
 591. Loher, W. Circadian control of spermatophore formation in the cricket Teleogryllus commodus Walker. J. Insect Physiol. 20: 1155–1172, 1974.
 592. Loher, W., and M. K. Chandrashekaran. Circadian rhythmicity in the oviposition of the grasshopper Chorthippus curtipennis. J. Insect Physiol. 16: 1677–1688, 1970.
 593. Loudon, A.S.I., and B. R. Brinklow. Melatonin implants prevent the onset of seasonal quiescence and suppress the release of prolactin in response to a dopamine antagonist in the Bennett's wallaby (Macropus rufogriseus rufogriseus). J. Reprod. Fertil. 90: 611–618, 1990.
 594. Luiten, P.G.M., G. J. ter Horst, H. Karst, and A. B. Steffens. The course of paraventricular hypothalamic efferents to autonomic structures in medulla and spinal cord. Brain Res. 329: 374–378, 1984.
 595. Lukat, R. Circadian growth layers in the cuticle of behaviorally arrhythmic cockroaches (Blaberus fuscus, Ins., Blattoidea). Experientia 34: 477, 1978.
 596. Lukat, R., and F. Weber. The structure of locomotor activity in bilobectomized cockroaches (Blaberus fuscus). Experientia 35: 38–39, 1979.
 597. Lynch, G. R., and A. L. Epstein. Melatonin induced changes in gonads, pelage and thermogenic characters in the white‐footed mouse, Peromyscus leucopus. Comp. Biochem. Physiol. [C] 53: 67–68, 1976.
 598. Lythgoe, J. N., and J. Shand. Endogenous circadian retinomotor movements in the neon tetra (Paracheirodon innesi). Invest. Ophthalmol. Vis. Sci. 24: 1203–1210, 1983.
 599. Malpaux, B., J. E. Robinson, M. B. Brown, and F. J. Karsch. Importance of changing photoperiod and melatonin secretory pattern in determining the length of the breeding season in the Suffolk ewe. J. Reprod. Fertil. 83: 461–470, 1988.
 600. Marcovitch, S. Plant lice and light exposure. Science 58: 537–538, 1923.
 601. Marcovitch, S. The migration of the Aphididae and the appearance of sexual forms as affected by the relative length of daily light exposure. J. Agricult. Res. 27: 513–522, 1924.
 602. Marcus, N. H. Photoperiodic control of diapause in the marine calanoid copepod Labidocera aestiva. Biol. Bull. 159: 311–318, 1980.
 603. Marimuthu, G., S. Rajan, and M. K. Chandrashekaran. Social entrainment of the circadian rhythm in the flight activity of the microchiropteran bat Hipposideros speoris. Behav. Ecol. Sociobiol. 8: 147–150, 1981.
 604. Masaki, S. Seasonal and latitudinal adaptations in the life cycles of crickets. In: Evolution of insect migration and diapause. New York: Springer‐Verlag, 1978.
 605. Masaki, S., and T. J. Walker. Cricket life cycles. In: Evolutionary Biology, edited by M. K. Hecht, B. Wallace, and G. T. Prance. New York: Plenum, 1987, vol. 2, p. 349–423.
 606. Mason, R., and A. Brooks. The electrophysiological effects of melatonin and a putative melatonin antagonist (N‐acetyltryptamine) on rat suprachiasmatic neurones in vitro. Neurosci. Lett. 95: 296–301, 1988.
 607. Mason, R., M. E. Harrington, and B. Rusak. Electrophysiological responses of hamster suprachiasmatic neurones to neuropeptide Y in the hypothalamic slice preparation. Neurosci. Lett. 80: 173–179, 1987.
 608. Mason, R., and B. Rusak. Neurophysiological responses to melatonin in the SCN of short‐day sensitive and refractory hamsters. Brain Res. 533: 15–19, 1990.
 609. Masson‐Pévet, M., P. Pévet, and B. Vivien‐Roels. Pinealectomy and constant release of melatonin or 5‐methoxytryptamine induce testicular atrophy in the European hamster (Cricetus cricetus, L). J. Pineal Res. 4: 79–88, 1987.
 610. Maywood, E. S., R. C. Buttery, G.H.S. Vance, J. Herbert, and M. H. Hastings. Gonadal responses of the male Syrian hamster to programmed infusions of melatonin are sensitive to signal duration and frequency but not to signal phase nor to lesions of the suprachiasmatic nuclei. Biol. Reprod. 43: 174–182, 1990.
 611. McArthur, A. J., M. U. Gillette, and R. A. Prosser. Melatonin directly resets the rat suprachiasmatic circadian clock in vitro. Brain Res. 565: 158–161, 1991.
 612. McCrone, E. J., and P. G. Sokolove. Brain–gonad axis and photoperiodically‐stimulated sexual maturation in the slug, Limax maximus. J. Comp. Physiol. 133: 117–123, 1979.
 613. McGuire, R. A., W. M. Rand, and R. J. Wurtman. Entrainment of the body temperature rhythm in rats: effect of color and intensity of environmental light. Science 181: 956–957, 1973.
 614. McMahon, D. G., and G. D. Block. The Bulla ocular circadian pacemaker I: pacemaker neuron membrane potential controls phase through a calcium dependent mechanism. J. Comp. Physiol. [A] 161: 335–346, 1987.
 615. McMahon, D. G., and G. D. Block. The Bulla ocular circadian pacemaker II: pacemaker membrane potential regulates the freerunning period of the oscillator. J. Comp. Physiol. [A] 161: 347–354, 1987.
 616. McMillan, J. P. Pinealectomy abolishes the circadian rhythm of migratory restlessness. J. Comp. Physiol. 79: 105–112, 1972.
 617. McMillan, J. P., J. A. Elliott, and M. Menaker. On the role of eyes and brain photoreceptors in the sparrow: arrhythmicity in constant light. J. Comp. Physiol. 102: 263–268, 1975.
 618. McMillan, J. P., H. C. Keatts, and M. Menaker. On the role of eyes and brain photoreceptors in the sparrow: entrainment to light cycles. J. Comp. Physiol. 102: 251–256, 1975.
 619. McMillan, J. P., H. A. Underwood, J. A. Elliott, M. H. Stetson, and M. Menaker. Extraretinal light perception in the sparrow IV. Further evidence that the eyes do not participate in photoperiodic photoreception. J. Comp. Physiol. 97: 205–213, 1975.
 620. McNulty, J. A. Functional morphology of the pineal complex in cyclostomes, elasmobranchs, and bony fishes. In: Pineal Research Reviews, edited by R. J. Reiter. New York: Liss, 1984, vol. 2, p. 1–40.
 621. Meijer, J. H., G. A. Groos, and B. Rusak. Luminance coding in a circadian pacemaker: the suprachiasmatic nucleus of the rat and the hamster. Brain Res. 382: 109–118, 1986.
 622. Meijer, J. H., and W. J. Rietveld. Neurophysiology of the suprachiasmatic circadian pacemaker in rodents. Physiol. Rev. 69: 671–707, 1989.
 623. Meijer, J. H., E. van der Zee, and M. Dietz. The effects of intraventricular carbachol injections on the free‐running activity rhythm of the hamster. J. Biol. Rhythms 3: 333–348, 1988.
 624. Meijer, J. H., E. A. van der Zee, and M. Dietz. Glutamate phase shifts circadian activity rhythms in hamsters. Neurosci. Lett. 86: 177–183, 1988.
 625. Menaker, M. Extraretinal light perception in the sparrow I. Entrainment of the biological clock. Proc. Natl. Acad. Sci. U.S.A. 59: 414–421, 1968.
 626. Menaker, M. Rhythms, reproduction, and photoreception. Biol. Reprod. 4: 295–308, 1971.
 627. Menaker, M. Eyes—the second (and third) pineal glands? In: Photoperiodism, Melatonin and the Pineal, edited by D. Evered and S. Clark. London: Pitman, 1985, p. 78–87.
 628. Menaker, M., and A. Eskin. Entrainment of circadian rhythms by sound in Passer domesticus. Science 154: 1579–1581, 1966.
 629. Menaker, M., and H. Keatts. Extraretinal light perception in the sparrow II. Photoperiodic stimulation of testicular growth. Proc. Natl. Acad. Sci. U.S.A. 60: 146–151, 1968.
 630. Menaker, M., R. Roberts, J. Elliott, and H. Underwood. Extraretinal light perception in the sparrow III. The eyes do not participate in photoperiodic photoreception. Proc. Natl. Acad. Sci. U.S.A. 67: 320–325, 1970.
 631. Menaker, M., and H. Underwood. Extraretinal photoreception in birds. Photochem. Photobiol. 23: 299–306, 1976.
 632. Menaker, M., and S. Wisner. Temperature‐compensated circadian clock in the pineal of Anolis. Proc. Natl. Acad. Sci. U.S.A. 80: 6119–6121, 1983.
 633. Michel, S., M. Geusz, J. Zaritsky, and G. Block. Circadian rhythm in membrane conductance expressed in isolated neurons. Science 259: 239–241, 1993.
 634. Miller, M. M., J. Silver, and R. B. Billiar. Effects of ovariectomy on the binding of [125I]‐bungarotoxin (2.2 and 3.3) to the suprachiasmatic nucleus of the hypothalamus: an in vivo autoradiographic analysis. Brain Res. 247: 355–364, 1982.
 635. Miller, M. M., J. Silver, and R. B. Billiar. Effects of gonadal steroids on the in vivo binding of [125I]‐bungarotoxin to the suprachiasmatic nucleus. Brain Res. 290: 67–75, 1984.
 636. Minutini, L., A. Innocenti, C. Bertolucci, and A. Foà. Circadian organization in the ruin lizard Podarcis sicula: the role of the suprachiasmatic nuclei of the hypothalamus. J. Comp. Physiol. [A] 176: 281–288, 1995.
 637. Misra, C., and J. P. Thapliyal. Time of administration of indolamines and testicular response of Indian garden lizard Calotes versicolor. Indian J. Exp. Biol. 17: 1383–1385, 1979.
 638. Mistlberger, R. E. Effects of daily schedules of forced activity on free‐running rhythms in the rat. J. Biol. Rhythms 6: 71–80, 1991.
 639. Mistlberger, R. E., and A. Rechtschaffen. Recovery of anticipatory activity to restricted feeding in rats with ventromedial hypothalamic lesions. Physiol. Behav. 33: 227–235, 1984.
 640. Mistlberger, R. E., and B. Rusak. Carbachol phase shifts circadian activity rhythms in ovariectomized rats. Neurosci. Lett. 72: 357–362, 1986.
 641. Mistlberger, R. E., and B. Rusak. Food‐anticipatory circadian rhythms in rats with paraventricular and lateral hypothalamic ablations. J. Biol. Rhythms 3: 277–291, 1988.
 642. Miyashita, K. Effect of photoperiod on the post‐overwinter development of a crab spider, Xysticus croceus Fox (Araneae, Thomisidae). Bull. Br. Arachnol. Soc. 8: 61–63, 1989.
 643. Mizoguchi, A., and H. Ishizaki. Prothoracic glands of the saturniid moth Samia cynthia ricini possess a circadian clock controlling gut purge timing. Proc. Natl. Acad. Sci. U.S.A. 79: 2726–2730, 1982.
 644. Mizoguchi, A., and H. Ishizaki. Circadian clock controlling gut‐purge rhythm of the saturniid Samia cynthia ricini: its characterization and entrainment mechanism. J. Comp. Physiol. [A] 155: 639–647, 1984.
 645. Mizoguchi, A., and H. Ishizaki. Further evidence for the presence of a circadian clock in the prothoracic glands of the saturnid moth Samia cynthia ricini: decapitated larvae can respond to light‐dark changes. Dev. Growth Differ. 26: 607–611, 1984.
 646. Moffett, J. R., L. Williamson, M. Palkovits, and M.A.A. Namboodiri. N‐acetylaspartylglutamate: a transmitter candidate for the retinohypothalamic tract. Proc. Natl. Acad. Sci. U.S.A. 87: 8065–8069, 1990.
 647. Moore, F. L. Regulation of reproductive behaviors. In: Hormones and Reproduction in Fishes, Amphibians and Reptiles, edited by D. O. Norris and R. E. Jones. New York: Plenum, 1987, p. 505–522.
 648. Moore, F. L., and P. Deviche. Neuroendocrine processing of environmental information in amphibians. In: Processing of Environmental Information in Vertebrates, edited by M. H. Stetson, New York: Springer‐Verlag, 1988, p. 19–45.
 649. Moore, R. Y., and V. B. Eichler. Loss of a circadian adrenal corticosterone rhythm following suprachiasmatic lesions in the rat. Brain Res. 42: 201–206, 1972.
 650. Moore, R. Y., and N. J. Lenn. A retinohypothalamic projection in the rat. J. Comp. Neurol. 146: 1–14, 1972.
 651. Moore‐Ede, M. C., F. M. Sulzman, and C. A. Fuller. The Clocks That Time Us. Cambridge, MA: Harvard Univ. Press, 1982.
 652. Morgan, P. J., G. Davidson, W. Lawson, and P. Barrett. Both pertussis toxin‐sensitive and insensitive G‐proteins link melatonin receptor to inhibition of adenylate cyclase in the ovine pars tuberalis. J. Neuroendocrinal. 2: 773–776, 1990.
 653. Morgan, P. J., W. Lawson, and G. Davidson. Interaction of forskolin and melatonin on cyclic AMP generation in pars tuberalis cells of ovine pituitary. J. Neuroendocrinal. 3: 497–501, 1991.
 654. Morgan, P. J., L. M. Williams, G. Davidson, W. Lawson, and E. Howell. Melatonin receptors on ovine pars tuberalis: characterization and autoradiographic localization. J. Neuroendocrinal. 1: 1–4, 1989.
 655. Moriaty, F. Egg diapause and water absorption in the grasshopper Chorthippus brunneus. J. Insect Physiol. 15: 2069–2074, 1969.
 656. Morin, L. P. Effect of ovarian hormones on synchrony of hamster circadian rhythms. Physiol. Behav. 24: 741–749, 1980.
 657. Morin, L. P. Propylthiouracil, but not other antithyroid treatments, lengthens hamster circadian period. Am. J. Physiol. 255 (Regulatory Integrative Comp. Physiol. 26): R1–R5, 1988.
 658. Morin, L. P., and L. A. Cummings. Effect of surgical or photoperiodic castration, testosterone replacement or pinealectomy on male hamster running rhythmicity. Physiol. Behav. 26: 825–838, 1981.
 659. Morin, L. P., and L. A. Cummings. Splitting of wheelrunning rhythms by castrated or steroid treated male and female hamsters. Physiol. Behav. 29: 665–675, 1982.
 660. Morin, L. P., K. M. Fitzgerald, and I. Zucker. Estradiol shortens the period of hamster circadian rhythms. Science 196: 305–307, 1977.
 661. Morin, L. P., M. L. Gavin, and J. E. Ottenweller. Propylthiouracil causes phase delays and circadian period lengthening in male and female hamsters. Am. J. Physiol. 250 (Regulatory Integrative Comp. Physiol. 21): R151–R160, 1986.
 662. Morita, Y., S. Tamotsu, and K. Uchida. Multiplicity of electrophysiological and immunocytochemical properties in the pineal photosensory system. In: Advances in Pineal Research, edited by R. J. Reiter and S. F. Pang. London: Libbey, 1989, vol. 3, p. 43–48.
 663. Morita, Y., K. Uchida, S. Tamotsu, M. Samejima, and T. Kanamura. Electrophysiological basis of photic entrainment by pineal photosensory system. In: Advances in Pineal Research, edited by A. Foldes and R. J. Reiter. London: Libbey, 1991, vol. 6, p. 37–46.
 664. Morris, M. C., and R. D. Lewis. Simulation of insect thermoperiodic response curves using a damped circadian oscillator model. J. Interdiscip. Cycle Res. 21: 153–160, 1990.
 665. Mote, M. I., and K. R. Black. Action spectrum and threshold sensitivity of entrainment of circadian running activity in the cockroach Periplaneta americana. Photochem. Photobiol. 34: 257–265, 1981.
 666. Mote, M. I., and T. H. Goldsmith. Spectral sensitivities of color receptors in the compound eye of Periplaneta americana. J. Exp. Zool. 173: 137–146, 1970.
 667. Mrosovsky, N. Circannual cycles in golden‐mantled ground squirrels: phase shift produced by low temperatures. J. Comp. Physiol. 136: 349–353, 1980.
 668. Mrosovsky, N. Phase response curves for social entrainment. J. Comp. Physiol. [A] 162: 35–46, 1988.
 669. Mrosovsky, N. Circannual cycles in golden‐mantled ground squirrels: fall and spring cold pulses. J. Comp. Physiol. [A] 167: 683–689, 1990.
 670. Mrosovsky, N., S. G. Reebs, G. I. Honrado, and P. A. Salmon. Behavioural entrainment of circadian rhythms. Experientia 45: 696–702, 1989.
 671. Müller, H. J. Die Wirkung Exogener Faktoren auf die Zyklische Formenbildung der Insekten, Inbesondere der Gattung Euscelis Horn. (Auchenorrhyncha). Zool. Jahrbuecher Syst. 85: 317–430, 1957.
 672. Müller, H. J. Über den Einfluss der Photoperiode auf Diapause and Korpergrosse der Delphacide Stenocranus minutus Fabr. (Homoptera Auchenorrhyncha). Zool. Anz. 160: 294–311, 1959.
 673. Murakami, N., K. Takahashi, and K. Kawashima. Effect of light on the acetylcholine concentrations of the suprachiasmatic nucleus in the rat. Brain Res. 311: 358–360, 1984.
 674. Murakami, N., M. Takamure, K. Takahashi, K. Utunomiya, H. Kuroda, and T. Etoh. Long‐term cultured neurons from rat suprachiasmatic nucleus retain the capacity for circadian oscillation of vasopressin release. Brain Res. 545: 347–350, 1991.
 675. Murton, R. K., B. Lofts, and N. J. Westwood. The circadian basis of photoperiodically controlled spermatogenesis in the greenfinch Chloris chloris. J. Zool. 161: 125–136, 1970.
 676. Nadakavukaran, J., M. Lickey, and W. Jordon. Regulation of the circadian clock in the Aplysia eye. J. Neurosci. 6: 14–21, 1986.
 677. Nanda, K. K., and K. C. Hamner. Studies on the nature of the endogenous rhythm affecting photoperiodic response of Biloxi soybean. Bot. Gaz. 120: 14–25, 1958.
 678. Nelson, D. E., and J. S. Takahashi. Sensitivity and integration in a visual pathway for circadian entrainment in the hamster (Mesocricetus auratus). J. Physiol. 439: 115–145, 1991.
 679. Nelson, R. J., R. T. Mason, R. W. Krohmer, and D. Crews. Pinealectomy blocks vernal courtship behavior in red‐sided garter snakes. Physiol. Behav. 39: 231–233, 1987.
 680. Nicholls, T. J., A. R. Goldsmith, and A. Dawson. Photorefractoriness in birds and comparison with mammals. Physiol. Rev. 68: 133–176, 1988.
 681. Nishiitsutsuji‐Uwo, J., S. F. Petropulos, and C. S. Pittendrigh. Central nervous system control of circadian rhythmicity in the cockroach. I. Role of the pars intercerebralis. Biol. Bull. 133: 679–696, 1967.
 682. Nishiitsutsuji‐Uwo, J., and C. S. Pittendrigh. Central nervous system control of circadian rhythmicity in the cockroach. II. The pathway of light signals that entrain the rhythms. Z. Vergl. Physiol. 58: 1–13, 1968.
 683. Nishiitsutsuji‐Uwo, J., and C. S. Pittendrigh. Central nervous system control of circadian rhythmicity in the cockroach. III. The optic lobes, locus of the driving oscillation? Z. Vergl. Physiol. 58: 14–46, 1968.
 684. Norgren, R. B., Jr., and R. Silver. Retinohypothalamic projections and the suprachiasmatic nucleus in birds. Brain Behav. Evol. 34: 73–83, 1989.
 685. Nowak, J. Z., and E. Zurawska. Dopamine in the rabbit retina and striatum: diurnal rhythm and effect of light stimulation. J. Neural Transm. 75: 201–212, 1989.
 686. Numata, H. Temporal variation in the photoperiodic induction and termination of adult diapause in the bean bug, Riptortus clavatus. J. Insect Physiol. 38: 447–452, 1992.
 687. Numata, H., and T. Hidaka. Compound eyes as the photoperiodic receptors in the bean bug. Experientia 39: 868–869, 1983.
 688. Numata, H., and T. Hidaka. Photoreceptors in the bean bug, Riptortus clavatus. Rostria 38: 571–580, 1987.
 689. Ohi, K., M. Takashima, T. Nishikawa, and K. Takahashi. N‐methyl‐d‐aspartate receptor participates in neuronal transmission of photic information through the retinohypothalamic tract. Neuroendocrinology 53: 344–348, 1991.
 690. Oishi, T., and J. K. Lauber. Photoreception in the photosexual response of quail. I. Site of photoreceptor. Am. J. Physiol. 225: 155–158, 1973.
 691. Oishi, T., and J. K. Lauber. Photoreception in the photosexual response of quail. II. Effects of intensity and wavelength. Am. J. Physiol. 225: 880–886, 1973.
 692. Okamura, H., A. Berod, J.‐F. Julien, M. Geffard, K. Kitahama, J. Mallet, and P. Bobillier. Demonstration of GABAergic cell bodies in the suprachiasmatic nucleus: in situ hybridization of glutamic acid decarboxylase (GAD) mRNA and immunocytochemistry of GAD and GABA. Neurosci. Lett. 102: 131–136, 1989.
 693. Okamura, H., S. Murakami, K. Uda, T. Sugano, Y. Takahashi, C. Yanaihara, N. Yanaihara, and Y. Ibata. Coexistence of vasoactive intestinal peptide (VIP)‐, peptide histidine isoleucine amide (PHI)‐, and gastrin releasing peptide (GRP)‐like immunoreactivity in neurons of the rat suprachiasmatic nucleus. Biomed. Res. 7: 295–299, 1986.
 694. Oksche, A., H. Kirschstein, H. Kobayashi, and D. S. Farner. Electron microscopic and experimental studies of the pineal organ in the white‐crowned sparrow, Zonotrichia leucophrys gambelii. Z. Zellforsch. 124: 247–274, 1972.
 695. Oliver, J., and J. D. Baylé. Étude de la réponse testiculaire à la photostimulation selective de l'hypothalamus basal ou de la région préoptique chez la caille. C. R. Acad. Sci. III 282: 571–574, 1976.
 696. Oliver, J., and J. D. Baylé. Brain photoreceptors for the photoinduced testicular response in birds. Experientia 38: 1021–1029, 1982.
 697. Ooi, V.E.C., and T. B. Ng. Histological studies on the effects of pineal 5‐methoxyindoles on the reproductive organs of the male golden hamster. J. Pineal Res. 7: 315–324, 1989.
 698. Ooka‐Souda, S., and H. Kabasawa. Circadian rhythms in locomotor activity of the hagfish, Eptatretus burgeri III. Hypothalamus: a locus of the circadian pacemaker? Zool. Sci. 5: 437–442, 1988.
 699. Ookawa, T. Some observations on behavior and reproductive organs in blinded chickens. Poultry Sci. 49: 1531–1535, 1970.
 700. Oshima, I., H. Yamada, M. Goto, K. Sato, and S. Ebihara. Pineal and retinal melatonin is involved in the control of circadian locomotor activity and body temperature rhythms in the pigeon. J. Comp. Physiol. [A] 166: 217–226, 1989.
 701. Ottenweller, J. E., W. N. Tapp, and B. H. Natelson. Phase‐shifting the light–dark cycle resets the food‐entrainable circadian pacemaker. Am. J. Physiol. 258 (Regulatory Integrative Comp. Physiol. 29): R994–R1000, 1990.
 702. Page, T. L. Interactions between bilaterally paired components of the cockroach circadian system. J. Comp. Physiol. 124: 225–236, 1978.
 703. Page, T. L. Effects of localized low‐temperature pulses on the cockroach circadian pacemaker. Am. J. Physiol. 240 (Regulatory Integrative Comp. Physiol. 11): R144–R150, 1981.
 704. Page, T. L. Neural and endocrine control of circadian rhythmicity in invertebrates. In: Biological Rhythms. Handbook of Behavioral Neurobiology, edited by J. Aschoff. New York: Plenum, 1981, vol. 4, p. 145–172.
 705. Page, T. L. Extraretinal photoreception in entrainment and photoperiodism in invertebrates. Experientia 38: 1007–1013, 1982.
 706. Page, T. L. Transplantation of the cockroach circadian pacemaker. Science 216: 73–75, 1982.
 707. Page, T. L. Effects of optic‐tract regeneration on internal coupling in the circadian system of the cockroach. J. Comp. Physiol. 153: 231–240, 1983.
 708. Page, T. L. Regeneration of the optic tracts and circadian pacemaker activity in the cockroach Leucophaea maderae. J. Comp. Physiol. 152: 231–240, 1983.
 709. Page, T. L. Neuronal organization of a circadian clock in the cockroach Leucophaea maderae. In: Photoperiodic Regulation of Insect and Molluscan Hormones, edited by R. Porter and G. Collins. London: Pitman, 1984, p. 115–135.
 710. Page, T. L. Circadian organization in the cockroach: effects of temperature cycles on locomotor activity. J. Insect Physiol. 31: 235–242, 1985.
 711. Page, T. L. Clocks and circadian rhythms in insects. In: Comprehensive Insect Biochemistry, Physiology, and Pharmacology VI. Sensory Physiology, edited by G. Kerkut and L. Gilbert. Oxford: Pergamon, 1985, p. 577–652.
 712. Page, T. L. Serotonin phase shifts the circadian rhythm of locomotor activity in the cockroach. J. Biol. Rhythms 2: 23–34, 1987.
 713. Page, T. L. Circadian organization and the representation of circadian information in the nervous systems of invertebrates. In: Trends in Chronobiology, edited by W. Th. J. M. Hekkens, G. A. Kerkhof and W. J. Rietveld. Oxford: Pergamon, 1988, p. 67–79.
 714. Page, T. L. Circadian organization in the cockroach. In: Cockroaches as Models for Neurobiology: Applications in Biomedical Research, edited by I. Huber. Boca Raton, FL: CRC, 1990, p. 225–246.
 715. Page, T. L. Circadian rhythms of locomotor activity in cockroach nymphs: freerunning and entrainment. J. Biol. Rhythms 5: 273–290, 1990.
 716. Page, T. L., and R. K. Barrett. Effects of light on circadian pacemaker development. II. The response to light. J. Comp. Physiol. [A] 165: 51–59, 1989.
 717. Page, T. L., and G. D. Block. Circadian rhythmicity in cockroaches: effects of early post‐embryonic development and aging. Physiol. Enlomol. 5: 271–281, 1980.
 718. Page, T. L., P. C. Caldarola, and C. S. Pittendrigh. Mutual entrainment of bilaterally distributed circadian pacemakers. Proc. Natl. Acad. Sci. U.S.A. 74: 1277–1281, 1977.
 719. Page, T. L., and J. L. Larimer. Entrainment of the circadian locomotor activity rhythm in crayfish. J. Comp. Physiol. 78: 107–120, 1972.
 720. Page, T. L., and J. L. Larimer. Neural control of circadian rhythmicity in the crayfish I. The locomotor activity rhythm. J. Comp. Physiol. 97: 59–80, 1975.
 721. Page, T. L., and J. L. Larimer. Neural control of circadian rhythmicity in the crayfish II. The ERG amplitude rhythm. J. Comp. Physiol. 97: 81–96, 1975.
 722. Page, T. L., and J. L. Larimer. Extraretinal photoreception in entrainment of crustacean rhythms. Photochem. Photobiol. 23: 245–251, 1976.
 723. Page, T. L., and K. G. Nalovic. Properties of mutual coupling between the two circadian pacemakers in the eyes of the mollusk Bulla gouldiana. J. Biol. Rhythms 7: 213–226, 1992.
 724. Paietta, J. Photooxidation and the evolution of circadian rhythmicity. J. Theor. Biol. 97: 77–82, 1982.
 725. Paniagua, R., B. Fraile, and F. J. Saez. Effects of photoperiod and temperature on testicular function in amphibians. Histol. Histopathol. 5: 365–378, 1990.
 726. Pauly, J. R., and N. D. Horseman. Anticholinergic agents do not block light‐induced circadian phase shifts. Brain Res. 348: 163–167, 1985.
 727. Pavgi, S., and A. Chandola. Photoperiodic time measurement in seasonal reproduction of the weaver bird (Ploceus philippinus). Gen. Comp. Endocrinol. 52: 126–133, 1983.
 728. Paydar‐Ravandi, F., and A. H. Meier. Melatonin mediates alternation of seasonality in Syrian hamsters. Biol. Reprod. 40: 475–480, 1989.
 729. Pengelley, E. T., and J. Asmundson. The effect of light on the free running circannual rhythm of the golden‐mantled ground squirrel, Citellus lateralis. Comp. Biochem. Physiol. 32: 155–160, 1970.
 730. Pengelley, E. T., and K. C. Fisher. The effect of temperature and photoperiod on the yearly hibernating behavior of captive golden‐mantled ground squirrels (Citellus lateralis tescorum). Can. J. Zool. 41: 1103–1120, 1963.
 731. Pévet, P. Is 5‐methoxytryptamine a pineal hormone? Psychoneuroendocrinology 8: 61–73, 1983.
 732. Pévet, P. The role of the pineal gland in the photoperiodic control of reproduction in different hamster species. Reprod. Nutr. Dev. 28: 443–458, 1988.
 733. Pévet, P., and C. Haldar‐Misra. Daily 5‐methoxytryptamine injections inhibit short‐day‐induced testicular atrophy in golden hamsters. J. Neural Transm. 55: 95–99, 1982.
 734. Pévet, P., and C. Haldar‐Misra. Effect of 5‐methoxytryptamine on testicular atrophy induced by experimental or natural short photoperiods in the golden hamster (Mesocricetus auratus). J. Neural Transm. 55: 69–84, 1982.
 735. Pévet, P., and F. Raynaud. 5‐methoxytryptamine: physiological effects and possible mechanisms of action. In: Advances in Pineal Research, edited by R. J. Reiter and A. Lukaszyk. London: Libbey, 1990, p. 209–216.
 736. Pfaff, D., and M. Keiner. Atlas of estradiol‐concentrating cells in the control of the nervous system of the female rat. J. Comp. Neurol. 151: 121–128, 1973.
 737. Phillips, J. A., and H. J. Harlow. Long‐term effects of pinealectomy on the annual cycle of golden‐mantled ground squirrels, Spermophilus lateralis. J. Comp. Physiol. 146: 501–505, 1982.
 738. Phillips, J.L.M., and P. J. Mikulka. The effects of restricted food access upon locomotor activity in rats with suprachiasmatic nucleus lesions. Physiol. Behav. 23: 257–262, 1979.
 739. Pickard, G. E., M. R. Ralph, and M. Menaker. The intergeniculate leaflet partially mediates effects of light on circadian rhythms. J. Biol. Rhythms 2: 35–56, 1987.
 740. Pickard, G. E., and F. W. Turek. The hypothalamic paraventricular nucleus mediates the photoperiodic control of reproduction but not the effects of light on the circadian rhythm of activity. Neurosci. Lett. 43: 67–72, 1983.
 741. Pickard, G. E., and F. W. Turek. Effects of partial destruction of the suprachiasmatic nuclei on two circadian parameters: wheel‐running activity and short‐day induced testicular regression. J. Comp. Physiol. [A] 156: 803–815, 1985.
 742. Pierce, M. E., and J. C. Besharse. Melatonin and dopamine interactions in the regulation of rhythmic photoreceptor metabolism. In: Pineal and Retinal Relationships, edited by P. J. O'Brien and D. C. Klein. New York: Academic, 1986, p. 219–237.
 743. Pittendrigh, C. S. Biological clocks: the functions, ancient and modern, of circadian oscillations. In: Science in the Sixties, edited by D. L. Arm. Albuquerque: Univ. of New Mexico Press, 1965, p. 96–111.
 744. Pittendrigh. C. S. On the mechanism of the entrainment of a circadian rhythm by light cycles. In: Circadian Clocks, edited by J. Aschoff. Amsterdam: North‐Holland, 1965, p. 277–297.
 745. Pittendrigh, C. S. The circadian oscillation in Drosophila pseudoobscura pupae: a model for the photoperiodic clock. Z. Pflanzenphysiol. 54: 275–307, 1966.
 746. Pittendrigh, C. S. Circadian surfaces and the diversity of possible roles of circadian organization in photoperiodic induction. Proc. Natl. Acad. Sci. U.S.A. 69: 2734–2737, 1972.
 747. Pittendrigh, C. S. Circadian oscillations in cells and the circadian organization of multicellular systems. In: The Neurosciences: Third Study Program, edited by F. O. Schmitt and F. G. Worden. Cambridge, MA: MIT, 1974, p. 437–458.
 748. Pittendrigh, C. S. Circadian clocks: what are they? In: Molecular Basis of Circadian Rhythms, edited by J. W. Hastings and H. Schweiger. Berlin: Dahlem Konferenzen, 1976, p. 11–48.
 749. Pittendrigh, C. S. Circadian organization and the photoperiodic phenomena. In: Biological Clocks in Seasonal Reproductive Cycles, edited by B. K. Follett and D. E. Follett. Bristol: Wright, 1981, p. 1–35.
 750. Pittendrigh, C. S. The photoperiodic phenomena: seasonal modulation of the “day within.” J. Biol. Rhythms 3: 173–188, 1988.
 751. Pittendrigh, C. S., and P. C. Caldarola. General homeostasis of the frequency of circadian oscillations. Proc. Natl. Acad. Sci. U.S.A. 70: 2697–2701, 1973.
 752. Pittendrigh, C. S., and S. Daan. A functional analysis of circadian pacemakers in nocturnal rodents. V. Pacemaker structure: a clock for all seasons. J. Comp. Physiol. 106: 333–355, 1976.
 753. Pittendrigh, C. S., and D. H. Minis. The entrainment of circadian oscillations by light and their role as photoperiodic clocks. Am. Nat. 98: 261–294, 1964.
 754. Pittendrigh, C. S., and D. H. Minis. The photoperiodic time measurement in Pectinophora gossypiella and its relation to the circadian system in that species. In: Biochronometry, edited by M. Menaker. Washington, DC: National Academy of Sciences, 1971, p. 212–247.
 755. Pittendrigh, C. S., and T. Takamura. Temperature dependence and evolutionary adjustment of critical night length in insect photoperiodism. Proc. Natl. Acad. Sci. U.S.A. 84: 7169–7173, 1987.
 756. Pollard, T. G., and J. L. Larimer. Circadian rhythmicity of heart rate in the crayfish, Procambarus clarkii. J. Comp. Physiol. 57: 221–226, 1977.
 757. Pratt, B. L., and B. D. Goldman. Environmental influences upon circadian periodicity of Syrian hamsters. Physiol. Behav. 36: 91–95, 1986.
 758. Pratt, B. L., and B. D. Goldman. Maternal influence on activity rhythms and reproductive development in Djungarian hamster pups. Biol. Reprod. 34: 655–663, 1986.
 759. Prosser, R. A., and M. U. Gillette. The mammalian circadian clock in the suprachiasmatic nuclei is reset in vitro by cAMP. J. Neurosci. 9: 1073–1081, 1989.
 760. Quay, W. B. Precocious entrainment and associated characteristics of activity patterns following pinealectomy and reversal of photoperiod. Physiol. Behav. 5: 1281–1291, 1970.
 761. Quay, W. B. Pineal Chemistry in Cellular and Physiological Mechanisms. Springfield, IL: Thomas, 1974.
 762. Quay, W. B. The parietal eye‐pineal complex. In: Biology of the Reptilia, edited by C. Gans. New York: Academic, 1979, vol. 9, p. 245–406.
 763. Raju, U., M. Nunez‐Regueiro, R. Cook, and A. Eskin. Characterization of a putative oscillator protein in the eye of Aplysia. Neurosci. Abstracts 16: 1332, 1990.
 764. Raju, U., S. Yeung, and A. Eskin. Involvement of proteins in light resetting ocular circadian oscillators of Aplysia. Am. J. Physiol. 258 (Regulatory Integrative Comp. Physiol. 29): R256–R262, 1990.
 765. Ralph, C. L. Melatonin production by extra‐pineal tissues. In: Melatonin—Current Status and Perspectives, edited by N. Birau and W. Chloot. New York: Pergamon, 1981, p. 35–46.
 766. Ralph, M. R., and G. D. Block. Circadian and light‐induced conductance changes in putative pacemaker cells of Bulla gouldiana. J. Comp. Physiol. 166: 589–595, 1990.
 767. Ralph, M. R., R. G. Foster, F. C. Davis, and M. Menaker. Transplanted suprachiasmatic nucleus determines circadian period. Science 247: 975–978, 1990.
 768. Ralph, M. R., and M. Menaker. Bicuculline blocks circadian phase delays but not advances. Brain Res. 325: 362–365, 1985.
 769. Ralph, M. R., and M. Menaker. Effects of diazepam on circadian phase‐advances and delays. Brain Res. 372: 405–408, 1986.
 770. Ralph, M. R., and M. Menaker. A mutation of the circadian system in golden hamsters. Science 241: 1225–1227, 1988.
 771. Ralph, M. R., and M. Menaker. GABA regulation of circadian responses to light. I. Involvement of GABAA‐benzodiazepine and GABAB receptors. J. Neurosci. 9: 2858–2865, 1989.
 772. Rankin, M. A. Hormonal control of insect migratory behaviour. In: Evolution of Insect Migration and Diapause, edited by H. Dingle. New York: Springer‐Verlag, 1978, p. 5–32.
 773. Rasenick, M. M., M. Neuburg, and S. J. Berry. Cyclic nucleotide activation of the silkmoth brain—cellular localization and further observations on the patterns of activation. J. Insect Physiol. 24: 137–139, 1978.
 774. Rastogi, R. K., L. Iela, P. K. Saxena, and G. Chieffi. The control of spermatogenesis in the green frog, Rana esculenta. J. Exp. Zool. 196: 151–165, 1976.
 775. Redman, J., S. Armstrong, and K. T. Ng. Free‐running activity rhythms in the rat: entrainment by melatonin. Science 219: 1089–1091, 1983.
 776. Reebs, S. G. Acoustical entrainment of circadian activity rhythms in house sparrows: constant light is not necessary. Ethology 80: 172–181, 1989.
 777. Reebs, S. G., R. J. Lavery, and N. Mrosovsky. Running activity mediates the phase‐advancing effects of dark pulses on hamster circadian rhythms. J. Comp. Physiol. [A] 165: 811–818, 1989.
 778. Reebs, S. G., and N. Mrosovsky. Effects of induced wheel running on the circadian activity rhythms of Syrian hamsters: entrainment and phase response curve. J. Biol. Rhythms 4: 39–48, 1989.
 779. Reebs, S. G., and N. Mrosovsky. Large phase‐shifts of circadian rhythms caused by induced running in a re‐entrainment paradigm: the role of pulse duration and light. J. Comp. Physiol. [A] 165: 819–825, 1989.
 780. Reiter, R. J. Effect of pineal grafts, pinealectomy and denervation of the pineal gland on the reproductive organs of male hamsters. Neuroendocrinology 2: 138–146, 1967.
 781. Reiter, R. J. The pineal gland and gonadal development in male rats and hamsters. Fertit. Steril. 19: 1009–1017, 1968.
 782. Reiter, R. J. The pineal and its hormones in the control of reproduction in mammals. Endocr. Rev. 1: 109–131, 1980.
 783. Reiter, R. J. (Ed). The Pineal Gland. New York: Raven, 1984.
 784. Reiter, R. J. The pineal gland and pubertal development in mammals: a state of the art assessment. In: The Pineal Gland during Development, edited by D. Gupta and R. J. Reiter. London: Croom‐Hehn, 1986, p. 100–116.
 785. Reiter, R. J. The mammalian pineal gland: its adaptive significance for reproductive response to environmental changes. S. Afr. J. Sci. 83: 651–656, 1987.
 786. Reiter, R. J. The melatonin message: duration versus coincidence hypotheses. Life Sci. 40: 2119–2131, 1987.
 787. Reiter, R. J. Pineal gland. Interface between the photoperiodic environment and the endocrine system. Trends Endocrinol. Metab. 2: 13–19, 1991.
 788. Reiter, R. J. Pineal melatonin: cell biology of its synthesis and of its physiological interactions. Endocr. Rev. 12: 151–180, 1991.
 789. Reiter, R. J., A. Holtorf, T. H. Champney, and M. K. Vaughan. Relative efficacy of melatonin and 5‐methoxytryptamine in terms of their antigonadotrophic and counterantigonadotrophic actions in male Syrian hamsters. J. Pineal Res. 1: 91–98, 1984.
 790. Reiter, R. J., P. K. Rudeen, and M. K. Vaughan. Restoration of fertility in light‐deprived female hamsters by chronic melatonin treatment. J. Comp. Physiol. 111: 7–13, 1976.
 791. Reiter, R. J., M. K. Vaughan, and P. J. Waring. Studies on the minimal dosage of melatonin required to inhibit pineal antigonadotrophic activity in male golden hamsters. Horm. Res. 6: 258–267, 1975.
 792. Remé, C. E., A. Wirz‐Justice, and M. Terman. The visual input stage of the mammalian circadian pacemaking system: I. Is there a clock in the mammalian eye? J. Biol. Rhythms 6: 5–29, 1991.
 793. Rence, B., and W. Loher. Arrhythmically singing crickets: thermoperiodic reentrainment after bilobectomy. Science 190: 385–387, 1975.
 794. Renner, M. The contribution of the honey bee to the study of time‐sense and astronomical orientation. Cold Spring Harb. Symp. Quant. Biol 25: 361–367, 1960.
 795. Rensing, L. Daily rhythmicity of corpus allatum and neurosecretory cells in Drosophila melanogaster (Meig). Science 144: 1586–1587, 1964.
 796. Repérant, J., J. P. Rio, D. Miceli, and M. Lemire. A radioautographic study of retinal projections in type I and type II lizards. Brain Res. 142: 401–411, 1978.
 797. Reppert, S. M., R. A. Chez, A. Anderson, and D. C. Klein. Maternal–fetal transfer of melatonin in the non‐human primate. Pediatr. Res. 13: 788–791, 1979.
 798. Reppert, S. M., R. J. Coleman, H. W. Heath, and J. R. Swedlow. Pineal N‐acetyltransferase activity in 10‐day‐old rats: a paradigm for studying the developing circadian system. Endocrinology 115: 918–925, 1984.
 799. Reppert, S. M., D. Henshaw, W. J. Schwartz, and D. R. Weaver. The circadian‐gated timing of birth in rats: disruption by maternal SCN lesions or by removal of the fetal brain. Brain Res. 403: 398–402, 1987.
 800. Reppert, S. M., M. J. Perlow, L. Tamarkin, and D. C. Klein. A diurnal melatonin rhythm in primate cerebrospinal fluid. Endocrinology 104: 295–301, 1979.
 801. Reppert, S. M., and W. J. Schwartz. Maternal coordination of the fetal biological clock in utero. Science 220: 969–971, 1983.
 802. Reppert, S. M., and W. J. Schwartz. The suprachiasmatic nuclei of the fetal rat: characterization of a functional circadian clock using 14C‐labeled deoxyglucose. J. Neurosci. 4: 1677–1682, 1984.
 803. Reppert, S. M., and W. J. Schwartz. Maternal endocrine extirpations do not abolish maternal coordination of the fetal circadian clock. Endocrinology 119: 1763–1767, 1986.
 804. Reppert, S. M., and W. J. Schwartz. Maternal suprachiasmatic nuclei are necessary for maternal coordination of the developing circadian system. J. Neurosci. 6: 2724–2729, 1986.
 805. Reppert, S. M., and G. R. Uhl. Vasopressin messenger ribonucleic acid in the supraoptic and suprachiasmatic nuclei: appearance and circadian regulation during development. Endocrinology 120: 2483–2487, 1987.
 806. Reppert, S. M., D. R. Weaver, V. M. Cassone, C. Godson, and L. F. Kolakowski, Jr. Melatonin receptors are for the birds: molecular analysis of two receptor subtypes differentially expressed in chick brain. Neuron 15: 1003–1015, 1995.
 807. Reppert, S. M., D. R. Weaver, and T. Ebisawa. Cloning and characterization of a mammalian melatonin receptor that mediates reproductive and circadian responses. Neuron 13: 1177–1185, 1994.
 808. Reppert, S. M., D. R. Weaver, S. A. Rivkees, and E. G. Stopa. Putative melatonin receptors in a human biological clock. Science 242: 78–81, 1988.
 809. Reviers, M., J. Ravault, Y. Tillet, and J. Pelletier. Melatonin binding sites in the sheep pars tuberalis. Neurosci. Lett. 100: 89–93, 1989.
 810. Rhodes, D. H. The influence of multiple photoperiods and pinealectomy on gonads, pelage and body weight in male meadow voles, Microtus pennsylvanicus. Comp. Biochem. Physiol. A93: 445–449, 1989.
 811. Richard, A. Role de la photoperiode dans le determinisme de maturation genitale femelle du cephalopde Sepia officinalis L. C. R. Hebd. Seances Acad. Sci. 264: 1315–1318, 1967.
 812. Richard, D. S., and D. S. Saunders. Prothoracic gland function in diapause and non‐diapause Sarcophaga argyrostoma and Calliphora vicina. J. Insect Physiol. 33: 385–392, 1987.
 813. Richter, C. P. Animal behavior and internal drives. Q. Rev. Biol. 2: 307–343, 1927.
 814. Richter, C. P. Sleep and activity: their relation to the 24‐hour clock. Proc. Assoc. Res. Nerv. Ment. Dis. 45: 8–27, 1967.
 815. Riemann, J. G., B. J. Thorson, and R. L. Rudd. Daily cycle of release of sperm from the testes of the Mediterranean flour moth. J. Insect Physiol. 20: 195–207, 1974.
 816. Rivkees, S. A., L. L. Carlson, and S. M. Reppert. Guanine nucleotide‐binding protein regulation of melatonin receptors in lizard brain. Proc. Natl. Acad. Sci. U.S.A. 86: 3882–3886, 1989.
 817. Rivkees, S. A., V. M. Cassone, D. R. Weaver, and S. M. Reppert. Melatonin receptors in chick brain: characterization and localization. Endocrinology 125: 363–368, 1989.
 818. Rivkees, S. A., C. A. Fox, C. D. Jacobson, and S. M. Reppert. Anatomic and functional development of the suprachiasmatic nuclei in the gray short‐tailed opossum. J. Neurosci. 8: 4269–4276, 1988.
 819. Rivkees, S. A., and S. M. Reppert. Entrainment of circadian phase in developing gray short‐tailed opossums: mother vs. environment. Am. J. Physiol. 259 (Endocrinol. Metab. 22): E384–E388, 1990.
 820. Roberts, M. H., and G. D. Block. Analysis of mutual circadian pacemaker coupling between the two eyes of Bulla. J. Biol. Rhythms 15: 55–75, 1985.
 821. Roberts, M. H., G. D. Block, and A. E. Lusska. Comparative studies of circadian pacemaker coupling in opisthobranch mollusks. Brain Res. 423: 286–292, 1987.
 822. Roberts, M. H., and R. Moore. Localization of neuropeptides in efferent terminals in the eye in the marine snail, Bulla. Cell Tissue Res. 248: 67–73, 1987.
 823. Roberts, S. K. Circadian activity in cockroaches. II. Entrainment and phase‐shifting. J. Cell. Comp. Physiol. 59: 175–186, 1962.
 824. Roberts, S. K. Photoreception and entrainment of cockroach activity rhythms. Science 148: 958–959, 1965.
 825. Roberts, S. K. Circadian activity rhythms in cockroaches. III. The role of endocrine and neural factors. J. Cell. Comp. Physiol. 67: 473–486, 1966.
 826. Roberts, S. K. Circadian rhythms in cockroaches: effects of optic lobe lesions. J. Comp. Physiol. 88: 21–30, 1974.
 827. Roberts, S. K., S. D. Skopik, and R. J. Driskill. Circadian rhythms in cockroaches: does brain hormone mediate the locomotor cycle? In: Biochronometry, edited by M. Menaker. Washington, DC: National Academy of Sciences, 1971, p. 505–515.
 828. Robinson, J. E. Endogenous annual rhythms of luteinizing hormone secretion in the ewe and their entrainment by photoperiod. In: Progress in Comparative Endocrinology, edited by A. Epple, C. G. Scanes, and M. H. Stetson. New York: Wiley, 1990, p. 653–658.
 829. Robinson, J. E., and F. J. Karsch. Photoperiodic history and a changing melatonin pattern can determine the neuroendocrine response of the ewe to daylength. J. Reprod. Fertil. 80: 159–165, 1987.
 830. Roff, D. The genetic basis of wing dimorphism in the sand cricket, Gryllus firmus, and its relevance to the evolution of wing dimorphism in insects. Heredity 57: 221–231, 1986.
 831. Rollag, M. D. Ability of tryptophan derivatives to mimic melatonin's action upon Syrian hamster reproductive system. Life Sci. 31: 2699–2707, 1982.
 832. Rollag, M. D., and M. H. Stetson. Melatonin injections into Syrian hamsters. In: The Pineal and Its Hormones, edited by R. J. Reiter. New York: Liss, 1982, p. 143–152.
 833. Rosenwasser, A. M. Behavioral neurobiology of circadian pacemakers: a comparative perspective. In: Progress in Psychobiology and Physiological Psychology, edited by A. N. Epstein and A. R. Morrison. New York: Academic, 1988, vol. 13, p. 155–226.
 834. Rosenwasser, A. M., and N. T. Adler. Structure and function in circadian timing systems: evidence for multiple coupled circadian oscillators. Neurosci. Biobehav. Rev. 10: 431–448, 1986.
 835. Rosenwasser, A. M., R. J. Pelchat, and N. T. Adler. Memory for feeding time: possible dependence on coupled circadian oscillators. Physiol. Behav. 32: 25–30, 1984.
 836. Ruis, J. F., L. M. Talamini, J. P. Buys, and W. J. Rietveld. Effects of time of feeding on recovery of food‐entrained rhythms during subsequent fasting in SCN‐lesioned rats. Physiol. Behav. 46: 857–866, 1989.
 837. Rusak, B. The role of the suprachiasmatic nuclei in the generation of circadian rhythms in the golden hamster, Mesocricetus auratus. J. Comp. Physiol. 118: 145–164, 1977.
 838. Rusak, B. Suprachiasmatic lesions prevent an antigonadal effect of melatonin. Biol. Reprod. 22: 148–154, 1980.
 839. Rusak, B., and K. G. Bina. Neurotransmitters in the mammalian circadian system. Annu. Rev. Neurosci. 13: 387–401, 1990.
 840. Rusak, B., and G. Groos. Suprachiasmatic stimulation phase shifts rodent circadian rhythms. Science 215: 1407–1409, 1982.
 841. Rusak, B., J. H. Meijer, and M. E. Harrington. Hamster circadian rhythms are phase‐shifted by electrical stimulation of the geniculo‐hypothalamic tract. Brain Res. 493: 283–291, 1989.
 842. Rusak, B., R. E. Mistlberger, B. Losier, and C. H. Jones. Daily hoarding entrains the pacemaker for hamster activity rhythms. J. Comp. Physiol. [A] 164: 165–171, 1988.
 843. Rusak, B., and L. P. Morin. Testicular responses to photoperiod are blocked by lesions of the suprachiasmatic nuclei in golden hamsters. Biol. Reprod. 15: 366–374, 1976.
 844. Rusak, B., H. A. Robertson, W. Wisden, and S. P. Hunt. Light pulses that shift rhythms induce gene expression in the suprachiasmatic nucleus. Science 248: 1237–1240, 1990.
 845. Rusak, B., and I. Zucker. Neural regulation of circadian rhythms. Physiol. Rev. 59: 449–526, 1979.
 846. Rust, C. C., and R. K. Meyer. Hair color, molt, and testis size in male, short‐tailed weasels treated with melatonin. Science 165: 921–922, 1969.
 847. Sack, R. L., A. J. Lewy, M. L. Blood, J. Stevenson, and L. D. Keith. Melatonin administration to blind people: phase advances and entrainment. J. Biol. Rhythms 6: 249–261, 1991.
 848. Sackman, J. W., J. C. Little, P. K. Rudeen, P. J. Waring, and R. J. Reiter. The effects of pineal indoles given late in the light period on reproductive organs and pituitary prolactin levels in male golden hamsters. Horm. Res. 8: 84–92, 1977.
 849. Saiovici, M. S., T. J. Nicholls, and B. K. Follett. Rapid photoperiodic responses in Japanese quail: is daylength measurement based upon a circadian system? J. Biol. Rhythms 2: 139–152, 1987.
 850. Saitoh, Y., Y. Matsui, I. Nihonmatsu, and H. Kawamura. Cross‐species transplantation of the suprachiasmatic nuclei from rats to Siberian chipmunks (Eutamias sibiricus) with suprachiasmatic lesions. Neurosci. Lett. 123: 77–91, 1991.
 851. Samel, A., H.‐M. Wegmann, M. Vejvoda, H. Maass, A. Gundel, and M. Schutz. Influence of melatonin treatment on human circadian rhythmicity before and after simulated 9–hr time shift. J. Biol. Rhythms 6: 235–248, 1991.
 852. Sanchez, J. A., and B. Fuentes‐Pardo. Circadian rhythm of the amplitude of the electroretinogram in the isolated eyestalk of the crayfish. Comp. Biochem. Physiol. 56: 601–605, 1977.
 853. Sandeman, D. C., R. E. Sandeman, and H. G. de Couet. Extraretinal photoreceptors in the brain of the crayfish Cherax destructor. J. Neurobiol. 21: 619–629, 1990.
 854. Sasaki, M., N. Murakami, and K. Takahashi. Critical period for the entrainment of the circadian rhythm in blinded pups by dams. Physiol. Behav. 33: 105–109, 1984.
 855. Sasaki, M., S. Yamazaki, and K. Chiba. Brain photoreception in the calling rhythm of a noctuid moth, Anadevidia peponis: method of making eyeless moth and micro‐irradiation of brain with fiber optics. Bull. Fac. Agricult. 27: 81–90, 1987.
 856. Saunders, D. S. Larval diapause of maternal origin. II. The effect of photoperiod and temperature on Nasonia vitripennis. J. Insect Physiol. 12: 569–581, 1966.
 857. Saunders, D. S. Larval diapause of maternal origin. III. The effect of host shortage on Nasonia vitripennis. J. Insect Physiol. 12: 899–908, 1966.
 858. Saunders, D. S. The temperature‐compensated photoperiod clock “programming” development and diapause in the flesh‐fly, Sarcophaga argyrostoma. J. Insect Physiol. 17: 801–812, 1971.
 859. Saunders, D. S. Orcadian control of larval growth rate in Sarcophaga argyrostoma. Proc. Natl. Acad. Sci. U.S.A. 69: 2738–2740, 1972.
 860. Saunders, D. S. The photoperiodic clock in the flesh‐fly, Sarcophaga argyrostoma. J. Insect Physiol. 19: 1941–1954, 1973.
 861. Saunders, D. S. Thermoperiodic control of diapause in an insect: theory of internal coincidence. Science 181: 358–360, 1973.
 862. Saunders, D. S. Manipulation of the length of the sensitive period, and the induction of pupal diapause in the flesh‐fly, Sarcophaga argyrostoma. J. Entomol. A 50: 107–118, 1975.
 863. Saunders, D. S. “Skeleton” photoperiods and the control of diapause and development in the flesh‐fly Sarcophaga argyrostroma. J. Comp. Physiol. 97: 97–112, 1975.
 864. Saunders, D. S. An experimental and theoretical analysis of photoperiodic induction in the flesh‐fly, Sarcophaga argyrostoma. J. Comp. Physiol. 124: 75–95, 1978.
 865. Saunders, D. S. External coincidence and the photoinducible phase in the Sarcophaga photoperiodic clock. J. Comp. Physiol. 132: 179–189, 1979.
 866. Saunders, D. S. Insect photoperiodism: entrainment within the circadian system as a basis for time measurement. In: Biological Clocks in Seasonal Reproductive Cycles, edited by B. K. Follet and D. E. Follet. Bristol: Scientechnia, 1981, p. 67–81.
 867. Saunders, D. S. Insect Clocks, 2nd ed. New York: Pergamon, 1982.
 868. Saunders, D. S. Photoperiodic induction of pupal diapause in Sarcophaga argyrostoma: temperature effects on circadian resonance. J. Insect Physiol. 28: 305–310, 1982.
 869. Saunders, D. S. Insect photoperiodism: the linden bug, Pyrrhocoris apterus, a species that measures daylength rather than nightlength. Experientia 43: 935–937, 1987.
 870. Saunders, D. S. The circadian basis of ovarian diapause regulation in Drosophila melanogaster: is the period gene causally involved in photoperiodic time measurement? J. Biol. Rhythms 5: 315–332, 1990.
 871. Saunders, D. S. The photoperiodic clock and “counter” in Sarcophaga argyrostoma: experimental evidence consistent with “external coincidence” in insect photoperiodism. J. Comp. Physiol. [A] 170: 121–127, 1992.
 872. Saunders, D. S., and L. J. Gilbert. Regulation of ovarian diapause in Drosophila melanogaster by photoperiod and moderately low temperature. J. Insect Physiol. 36: 195–200, 1990.
 873. Saunders, D. S., V. C. Henrich, and L. I. Gilbert. Induction of diapause in Drosophila melanogaster: photoperiodic regulation and the impact of arrhythmic clock mutations on time measurement. Proc. Natl. Acad. Sci. U.S.A. 86: 3748–3752, 1989.
 874. Saunders, D. S., and R. D. Lewis. A damped circadian oscillator model of an insect photoperiodic clock. II. Simulations of the shapes of the photoperiodic response curves. J. Theor. Biol. 128: 61–71, 1987.
 875. Saunders, D. S., and R. D. Lewis. A damped circadian oscillator model of an insect photoperiodic clock. III. Circadian and “hourglass” responses. J. Theor. Biol. 128: 73–85, 1987.
 876. Saunders, D. S., and R. D. Lewis. The photoperiodic clock and counter mechanism in two species of flies: evidence for damped circadian oscillators in time measurement. J. Comp. Physiol. [A] 163: 365–371, 1988.
 877. Saxena, P. K. Effect of single dose melatonin treatment on ovarian growth during the preparatory phase in Mystus tengara (Ham.). Anat. Anz. 147: 437–441, 1980.
 878. Saxena, P. K., and K. Anand. A comparison of ovarian recrudescence in the catfish, Mystus tengara (Ham.), exposed to short photoperiods, to long photoperiods, and to melatonin. Gen. Comp. Endocrinol. 33: 506–511, 1977.
 879. Saxena, R. N., L. Malhotra, R. Kant, and P. K. Baweja. Effect of pinealectomy and seasonal changes on pineal antigonadotropic activity of male Indian weaver bird Ploceus philippinus. Indian J. Exp. Biol. 17: 732–735, 1979.
 880. Sayler, A., and A. Wolfson. Avian pineal gland: progonadotropic response in the Japanese quail. Science 158: 1478–1479, 1967.
 881. Sayler, A., and A. Wolfson. Influence of the pineal gland on gonadal maturation in Japanese quail. Endocrinology 83: 1237–1246, 1968.
 882. Schleussner, G., and E. Gwinner. Photoperiodic time measurement during the termination of photorefractoriness in the starling (Sturnus vulgaris L.). Gen. Comp. Endocrinol. 75: 54–61, 1989.
 883. Schneiderman, H. A., and J. Horwitz. The induction and termination of facultative diapause in the chalcid wasps Mormoniella vitripennis (Walker) and Tritneptis klugii (Ratzeburg). J. Exp. Biol. 35: 520–551, 1958.
 884. Schull, J., J. Walker, K. Fitzgerald, L. Hilivirta, J. Ruckdeschel, D. Schumacher, D. Stranger, and D. L. McEachron. Effects of sex, thyro‐parathyroidectomy, and light regime on levels and circadian rhythms of wheel‐running in rats. Physiol. Behav. 46: 341–346, 1989.
 885. Schulz, W., U. Schluter, and G. Seifert. Extraocular photoreceptors in the brain of Epilachna varivestis (Coleoptera, Coccinellidae). Cell Tissue Res. 236: 317–320, 1984.
 886. Schwartz, W. J. Further evaluation of the tetrodotoxin‐resistant circadian pacemaker in the suprachiasmatic nuclei. J. Biol. Rhythms 6: 149–158, 1991.
 887. Schwartz, W. J. SCN metabolic activity in vivo. In: Suprachiasmatic Nucleus. The Mind's Clock, edited by D. C. Klein, R. Y. Moore, and S. M. Reppert. New York: Oxford Univ. Press, 1991, p. 144–156.
 888. Schwartz, W. J., R. A. Gross, and M. T. Morton. The suprachiasmatic nuclei contain a tetrodotoxin‐resistant circadian pacemaker. Proc. Natl. Acad. Sci. U.S.A. 84: 1694–1698, 1987.
 889. Schwartz, W. J., S. M. Reppert, S. M. Eagan, and M. C. Moore‐Ede. In vivo metabolic activity of the suprachiasmatic nuclei: a comparative study. Brain Res. 274: 184–187, 1983.
 890. Schwartz, W. J., and P. Zimmerman. Lesions of the suprachiasmatic nucleus disrupt circadian locomotor rhythms in the mouse. Physiol. Behav. 49: 1283–1287, 1991.
 891. Segal, E. Discussion to the paper of A. J. Marshall. Cold Spring Harb. Symp. Quant. Biol. 25: 504–505, 1960.
 892. Seron‐Ferré, M., M. Vergara, V. H. Parraguez, R. Riquelme, and A. J. Llanos. Fetal prolactin levels respond to a maternal melatonin implant. Endocrinology 125: 400–403, 1989.
 893. Seuge, J., and K. Veith. Diapause de Pieris brassicae: role des photorecepteurs cephaliques, etude des carotenoides cerebraux. J. Insect Physiol. 22: 1229–1235, 1976.
 894. Shapiro, A. M. Seasonal polyphenism. Evol. Biol. 9: 259–333, 1976.
 895. Shellabarger, C. J. Pinealectomy vs. pineal injections in the young cockerel. Endocrinology 51: 151–154, 1952.
 896. Shellabarger, C. J. Observations of the pineal in the white leghorn capon and cockerel. Poultry Sci. 32: 189–197, 1953.
 897. Shibata, S., V. M. Cassone, and R. Y. Moore. Effects of melatonin on neuronal activity in the rat suprachiasmatic nucleus in vitro. Neurosci. Lett. 97: 140–144, 1989.
 898. Shibata, S., S. Y. Liou, and S. Ueki. Influence of excitatory amino acid receptor antagonists and of baclofen on synaptic transmission in the optic nerve to the suprachiasmatic nucleus in slices of rat hypothalamus. Neuropharmacology 25: 403–409, 1986.
 899. Shibata, S., S. Y. Liou, S. Ueki, and Y. Oomura. Influence of environmental light‐dark cycle and enucleation on activity of suprachiasmatic neurons in slice preparation. Brain Res. 302: 75–81, 1984.
 900. Shibata, S., and R. Y. Moore. Development of a fetal circadian rhythm after disruption of the maternal circadian system. Dev. Brain Res. 41: 313–317, 1988.
 901. Shibata, S., and R. Y. Moore. Neuropeptide Y and vasopressin effects on rat suprachiasmatic nucleus neurons in vitro. J. Biol. Rhythms 3: 265–276, 1988.
 902. Shibata, S., Y. Oomura, K. Hattori, and H. Kita. Responses of suprachiasmatic nucleus neurons to optic nerve stimulation in rat hypothalamic slice preparation. Brain Res. 302: 83–89, 1984.
 903. Shimizu, I. Photoperiodic induction in the silkworm, Bombyx mori, reared on artificial diet: evidence for extraretinal photoreception. J. Insect Physiol. 28: 841–846, 1982.
 904. Shimizu, I., and K. Hasegawa. Photoperiodic induction of diapause in the silkworm, Bombyx mori: location of the photoreceptor using a chemiluminescent paint. Physiol. Entomol. 13: 81–88, 1988.
 905. Shimizu, I., and M. Kato. Carotenoid functions in photoperiodic induction in the silkworm, Bombyx mori. Photobiochem. Photobiophys. 7: 57–52, 1984.
 906. Shimizu, I., and K. Matsui. Photoreceptions in the eclosion of the silkworm Bombyx mori. Photochem. Photobiol. 37: 409–413, 1983.
 907. Silver, R., M. N. Lehman, M. Gibson, W. R. Gladstone, and E. L. Bittman. Dispersed cell suspensions of fetal SCN restore circadian rhythmicity in SCN‐lesioned adult hamsters. Brain Res. 525: 45–58, 1990.
 908. Silver, R., P. Witkovsky, P. Horvath, V. Alones, C. J. Barnstable, and M. N. Lehman. Coexpression of opsin‐ and VIP‐like immunoreactivity in CSF‐contacting neurons of the avian brain. Cell Tissue Res. 253: 189–198, 1988.
 909. Simpson, S. M., and B. K. Follett. Pineal and hypothalamic pacemakers: their role in regulating circadian rhythmicity in Japanese quail. J. Comp. Physiol. 144: 381–389, 1981.
 910. Simpson, S. M., and B. K. Follett. Formal properties of the circadian system underlying photoperiodic time‐measurement in Japanese quail. J. Comp. Physiol. 145: 381–390, 1982.
 911. Simpson, S. M., H. F. Urbanski, and J. E. Robinson. The pineal gland and the photoperiodic control of luteinizing hormone secretion in intact and castrated Japanese quail. J. Endocrinol. 99: 281–287, 1983.
 912. Siopes, T. D., and M. E. EI Halawani. Pineal and ocular influences on male and female turkeys: plasma luteinizing hormone and prolactin levels during gonadal development. Gen. Comp. Endocrinol. 73: 284–292, 1989.
 913. Siopes, T. D., and W. O. Wilson. Extraocular modification of photoreception in intact and pinealectomized Coturnix. Poultry Sci. 53: 2035–2041, 1974.
 914. Siopes, T. D., and W. O. Wilson. Participation of the eyes in the photosexual response of Japanese quail (Cotumix cotumix japonica). Biol. Reprod. 23: 352–357, 1980.
 915. Siuciak, J. A., J. Fang, and M. L. Dubocovich. Autoradiographic localization of 2‐[125I]iodomelatonin binding sites in the brains of C3H/HeN and C57BL / 6J strains of mice. Eur. J. Pharmacol. 180: 387–390, 1990.
 916. Siuciak, J. A., D. N. Krause, and M. L. Dubocovich. Quantitative pharmacological analysis of 2–125I‐iodomelatonin binding sites in discrete areas of the chicken brain. J. Neurosci. 11: 2855–2864, 1991.
 917. Skopik, S. D., and M. F. Bowen. Insect photoperiodism: an hourglass measures photoperiodic time in Ostrinia nubilalis. J. Comp. Physiol. 111: 249–259, 1976.
 918. Skopik, S. D., and C. S. Pittendrigh. Circadian systems. II. The oscillation in the individual Drosophila pupae: its independence of developmental stage. Proc. Natl. Acad. Sci. U.S.A. 58: 1862–1869, 1967.
 919. Smale, L., J. Dark, and I. Zucker. Pineal and photoperiodic influences on fat deposition, pelage, and testicular activity in male meadow voles. J. Biol. Rhythms 3: 349–355, 1988.
 920. Smith, R. D., S. I. T. Inouye, and F. W. Turek. Central administration of muscimol phase‐shifts the mammalian circadian clock. J. Comp. Physiol. [A] 164: 805–814, 1989.
 921. Smith, S. M., and R. A. Brust. Photoperiodic control of the maintenance and termination of larval diapause in Wyeomyia smithii (Coq.) with notes on oogenesis in the adult female. Can. J. Zool. 49: 1065–1073, 1971.
 922. Sokolove, P. G. Localization of the cockroach optic lobe circadian pacemaker with microlesions. Brain Res. 87: 13–21, 1975.
 923. Sokolove, P. G., J. Kirgan, and R. Tarr. Red light insensitivity of the extraocular pathway for photoperiodic stimulation of reproductive development in the slug, Limax maximus. J. Exp. Zool. 215: 219–223, 1981.
 924. Sokolove, P. G., and W. Loher. Role of eyes, optic lobes, and pars intercerebralis in locomotory and stridulatory circadian rhythms of Teleogryllus commodus. J. Insect Physiol. 21: 785–799, 1975.
 925. Stanfield, B., and W. M. Cowan. Evidence for a change in the retinohypothalamic projection in the rat following early removal of one eye. Brain Res. 104: 129–136, 1976.
 926. Stankov, B., B. Cozzi, V. Lucini, P. Fumagalli, F. Scaglione, and F. Fraschini. Characterization and mapping of melatonin receptors in the brain of three mammalian species: rabbit, horse, and sheep. Neuroendocrinology 53: 214–221, 1991.
 927. Stankov, B., and R. J. Reiter. Melatonin receptors: current status, facts, and hypotheses. Life Sci. 46: 971–982, 1990.
 928. Stanton, T. L., J. A. Siuciak, D. N. Krause, and M. L. Dubocovich. Autoradiographic localization of 2‐[125I]iodomelatonin binding sites in the brain of ground squirrels (Citellus lateralis). Soc. Neurosci. Abstr. 16: 773, 1990.
 929. Stebbins, R. C. Activity changes in the striped plateau lizard with evidence on influence of the parietal eye. Copeia 681–691, 1963.
 930. Steel, C. G. H., and A. D. Lees. The role of neurosecretion in the photoperiodic control of polymorphism in the aphid Megoura viciae. J. Exp. Biol. 67: 117–135, 1977.
 931. Steel, C. G. H., and E. J. Ampleford. Circadian control of haemolymph ecdysteroid titres and the ecdysis rhythm in Rhodnius prolixus. In: Photoperiodic Regulation of Insect and Mol‐luscan Hormones. London: Pitman, 1984, p. 150–163.
 932. Stehle, J. Melatonin binding sites in the brain of the 2‐day‐old chicken: an autoradiographic localisation. J. Neural Transm. 81: 83–89, 1990.
 933. Stein, H. Untersuchungen über den zeitsinn bei Vogeln. Z. Vergl. Physiol. 33: 387–403, 1951.
 934. Stephan, F. K. Limits of entrainment to periodic feeding in rats with suprachiasmatic lesions. J. Comp. Physiol. 143: 401–410, 1981.
 935. Stephan, F. K. Circadian rhythm dissociation induced by periodic feeding in rats with suprachiasmatic lesions. Behav. Brain Res. 7: 81–98, 1983.
 936. Stephan, F. K. Phase shifts of circadian rhythms in activity entrained to food access. Physiol. Behav. 32: 663–671, 1984.
 937. Stephan, F. K. Coupling between feeding‐ and light‐entrainable circadian pacemakers in the rat. Physiol. Behav. 38: 537–544, 1986.
 938. Stephan, F. K. Interaction between light‐ and feeding‐entrainable circadian rhythms in the rat. Physiol. Behav. 38: 127–133, 1986.
 939. Stephan, F. K. The role of period and phase in interactions between feeding‐ and light‐entrainable circadian rhythms. Physiol. Behav. 36: 151–158, 1986.
 940. Stephan, F. K. Entrainment of activity to multiple feeding times in rats with suprachiasmatic lesions. Physiol. Behav. 46: 489–497, 1989.
 941. Stephan, F. K. Forced dissociation of activity entrained to T cycles of food access in rats with suprachiasmatic lesions. J. Biol. Rhythms 4: 467–479, 1989.
 942. Stephan, F. K., K. J. Berkley, and R. L. Moss. Efferent connections of the rat suprachiasmatic nucleus. Neuroscience 6: 2625–2641, 1981.
 943. Stephan, F. K., and I. Zucker. Circadian rhythms in drinking behavior and locomotor activity are eliminated by hypothalamic lesions. Proc. Natl. Acad. Sci. U.S.A. 69: 1583–1586, 1972.
 944. Stetson, M. H., J. A. Elliott, and B. D. Goldman. Maternal transfer of photoperiodic information influences the photoperiodic response of prepubertal Djungarian hamsters (Phodopus sungorus sungorus). Biol. Reprod. 34: 664–669, 1986.
 945. Stetson, M. H., J. A. Elliott, and M. Menaker. Photoperiodic regulation of hamster testis: circadian sensitivity to the effects of light. Biol. Reprod. 13: 329–339, 1975.
 946. Stetson, M. H., K. S. Matt, and M. Watson‐Whitmyre. Photo‐periodism and reproduction in golden hamsters: circadian organization and the termination of photorefractoriness. Biol. Reprod. 14: 531–537, 1976.
 947. Stetson, M. H., S. L. Ray, N. Creyaufmiller, and T. H. Horton. Maternal transfer of photoperiodic information in Siberian hamsters. II. The nature of the maternal signal, time of signal transfer, and the effect of the maternal signal on peripubertal reproductive development in the absence of photoperiodic input. Biol. Reprod. 40: 458–465, 1989.
 948. Stetson, M. H., E. Sarafidis, and M. D. Rollag. Sensitivity of adult male Djungarian hamsters (Phodopus sungorus sungorus) to melatonin injections throughout the day: effects on the reproductive system and pineal. Biol. Reprod. 35: 618–623, 1986.
 949. Stetson, M. H., and D. E. Tay. Time course of sensitivity of golden hamsters to melatonin injections throughout the day. Biol. Reprod. 29: 432–438, 1983.
 950. Stetson, M. H., and M. Watson‐Whitmyre. Nucleus suprachi‐asmaticus: the biological clock in the hamster? Science 191: 197–199, 1976.
 951. Stetson, M. H., and M. Watson‐Whitmyre. Effects of exogenous and endogenous melatonin on gonadal function in hamsters. J. Neural Transm. Suppl. 21: 55–80, 1986.
 952. Stetson, M. H., M. Watson‐Whitmyre, and K. S. Matt. Termination of photorefractoriness in golden hamsters—photoperiodic requirements. J. Exp. Zool. 202: 81–88, 1977.
 953. Stetson, M. H., M. Watson‐Whitmyre, and B. Tate‐Ostroff. Role of the pineal and its hormone melatonin in the termination of photorefractoriness in golden hamsters. Biol. Reprod. 29: 689–696, 1983.
 954. Storey, C. R. Circadian photosensitivity in the photoperiodic control of gonadotrophin secretion in the canary, Serinus canarius. Gen. Comp. Endocrinol. 30: 198–203, 1976.
 955. Stross, R. G. Photoperiod control of diapause in Daphnia. III. Two‐stimulus control of long‐day, short‐day induction. Biol. Bull. 137: 359–374, 1969.
 956. Stross, R. G., and J. C. Hill. Diapause induction in Daphnia requires two stimuli. Science 150: 1462–1464, 1965.
 957. Strumwasser, F. Neural and humoral factors in the temporal organization of behavior. Physiologist 16: 9–42, 1973.
 958. Stumpf, W. E., and M. Sar. Anatomical distribution of estrogen, androgen, progestin, corticosteroid and thyroid hormone target sites in the brain of mammals: phylogeny and ontogeny. Am. Zool. 18: 435–445, 1979.
 959. Subbaraj, R., and E. Gwinner. Differential effects of testosterone on the circadian rhythms of locomotor activity and feeding in the European starling. Naturwissenschaften 72: 663–664, 1985.
 960. Sulzman, F. M., C. A. Fuller, and M. C. Moore‐Ede. Environmental synchronizers of squirrel monkey circadian rhythms. J. Appl. Physiol.: Respir. Environ. Exerc. Physiol. 43: 795–800, 1977.
 961. Sulzman, F. M., C. A. Fuller, and M. C. Moore‐Ede. Feeding time synchronizes primate circadian rhythms. Physiol. Behav. 18: 775–779, 1977.
 962. Sundararaj, B., and P. Keshavanath. Effects of melatonin and prolactin treatment on the hypophysial‐ovarian system in the catfish, Heteropneustes fossilis (Bloch). Gen. Comp. Endocrinol. 29: 84–96, 1976.
 963. Sundararaj, B., and S. Vasal. Photoperiod and temperature control in the regulation of reproduction in the female catfish. J. Fish Res. Bd. Can. 33: 959–973, 1976.
 964. Swann, J. M., and F. W. Turek. Multiple circadian oscillators regulate the timing of behavioral and endocrine rhythms in female golden hamsters. Science 228: 898–900, 1985.
 965. Swanson, L. W., and H.G.J.M. Kuypers. The paraventricular nucleus of the hypothalamus: cytoarchitectonic subdivisions and organization of projections to the pituitary, dorsal vagal complex and spinal cord as demonstrated by retrograde fluorescence double‐labeling methods. J. Comp. Neurol. 194: 555–570, 1980.
 966. Takahashi, J. S., P. J. de Coursey, L. Bauman, and M. Menaker. Spectral sensitivity of a novel photoreceptive system mediating entrainment of mammalian circadian rhythms. Nature 308: 186–188, 1984.
 967. Takahashi, J. S., H. Hamm, and M. Menaker. Circadian rhythms of melatonin release from individual superfused chicken pineal glands in vitro. Proc. Natl. Acad. Sci. U.S.A. 77: 2319–2322, 1980.
 968. Takahashi, J. S., and M. Menaker. Interaction of estradiol and progesterone: effects on circadian locomotor rhythm of female golden hamsters. Am. J. Physiol. 239 (Regulatory Integrative Comp. Physiol. 10): R497–R504, 1980.
 969. Takahashi, J. S., and M. Menaker. Role of the suprachiasmatic nuclei in the circadian system of the house sparrow, Passer domesticus. J. Neurosci. 2: 815–828, 1982.
 970. Takahashi, J. S., and M. Menaker. Multiple redundant circadian oscillators within the isolated avian pineal gland. J. Comp. Physiol. [A] 154: 435–440, 1984.
 971. Takahashi, J. S., N. Murakami, S. S. Nikaido, B. L. Pratt, and L. M. Robertson. The avian pineal, a vertebrate model system of the circadian oscillator: cellular regulation of circadian rhythms by light, second messengers, and macromolecular synthesis. Recent Prog. Horm. Res. 45: 279–352, 1989.
 972. Takahashi, J. S., D. Nelson, and A. Eskin. Immunocytochemi‐cal localization of serotonergic fibers innervating the ocular circadian system of Aplysia. Neuroscience 28: 139–147, 1989.
 973. Takahashi, K., and T. Deguchi. Entrainment of the circadian rhythms of blinded infant rats by nursing mothers. Physiol. Behav. 31: 373–378, 1983.
 974. Takahashi, K., N. Murakami, C. Hayafuji, and Y. Sasaki. Further evidence that circadian rhythm of blinded rat pups is entrained by the nursing dam. Am. J. Physiol. 246 (Regulatory Integrative Comp. Physiol. 17): R359–R363, 1984.
 975. Takeda, M., and S. D. Skopik. Geographic variation in the circadian system controlling photoperiodism in Ostrina nubi‐lalis. J. Comp. Physiol. [A] 156: 653–658, 1985.
 976. Tamarkin, L., C. W. Hollister, N. G. Lefebvre, and B. D. Goldman. Melatonin induction of gonadal quiescence in pi‐nealectomized Syrian hamsters. Science 198: 953–955, 1977.
 977. Tamarkin, L., W. K. Westrom, A. I. Hamill, and B. D. Goldman. Effect of melatonin on the reproductive systems of male and female hamsters: a diurnal rhythm in sensitivity to melatonin. Endocrinology 99: 1534–1541, 1976.
 978. Tanaka, K. Diapause and seasonal life cycle strategy in the house spider, Achaeranea tepidariorum (Araneae, Theridiidae). Physiol. Entomol. 16: 249–262, 1991.
 979. Tanaka, Y. Studies on hibernation with special reference to photoperiodicity and breeding of the Chinese Tussar silkworm. J. Sericultural Sci. Jpn. 19: 580–590, 1950.
 980. Tanaka, Y. Studies on hibernation with special reference to photoperiodicity and breeding of the Chinese Tussar silkworm. J. Sericultural Sci. Jpn. 20: 132–138, 1951.
 981. Tauber, M. J., and C. A. Tauber. Photoperiodic induction and termination of diapause in an insect: response to changing day lengths. Science 167: 170, 1970.
 982. Tauber, M. J., and C. A. Tauber. Quantitative response to daylength during diapause in insects. Nature 244: 296–297, 1973.
 983. Tauber, M. J., and C. A. Tauber. Developmental requirements of the univoltine species Chrysopa downesi: photoperiodic stimuli and sensitive stages. J. Insect Physiol. 22: 331–335, 1976.
 984. Tauber, M. J., C. A. Tauber, and C. J. Denys. Adult diapause in Chrysopa carnea: photoperiodic control of duration and colour. J. Insect Physiol. 16: 949–955, 1970.
 985. Tewary, P. D., and V. Kumar. Circadian periodicity and the initiation of gonadal growth in male blackheaded bunting (Emberiza melanocephala). J. Comp. Physiol. 144: 201–203, 1981.
 986. Tewary, P. D., and P. M. Tripathi. Circadian periodicity in termination of photorefractoriness in the yellow‐throated sparrow. Experientia 41: 1350–1351, 1985.
 987. Thapliyal, J. P., and C. Haldar. Effect of pinealectomy on the photoperiodic gonadal response of the Indian garden lizard, Calotes versicolor. Gen. Comp. Endocrinol. 39: 79–86, 1979.
 988. Thiele, H. U. The control of larval hibernation and adult aestivation in the carabid beetles Hebria brevicollis F. and Patrobus atrorufus. Oecologia 2: 347–361, 1969.
 989. Thiele, H. U. Die steuerung der jahresrhythmik von carabiden durch exogene und endogene faktoren. Zool. Jahrbuecher Abt. Syst. Okol. Georgr. Tiere 98: 341–371, 1971.
 990. Thiele, H. U. Differences in measurement of day‐length and photoperiodism in two stocks for subarctic and temperate climates in the carabid beetle Pterostichus nigrita F. Oecologia 30: 349–365, 1977.
 991. Thiele, H. U. Measurement of day‐length as a basis for photoperiodism and annual periodicity in the carabid beetle Pterostichus nigrita F. Oecologia 30: 331–348, 1977.
 992. Thorson, B. J., and J. G. Riemann. Abdominally entrained periodicities of testis and vas deferens activity in the Mediterranean flour moth. J. Insect Physiol. 23: 1189–1197, 1977.
 993. Tomioka, K. Residual circadian rhythmicity after bilateral lamina‐medulla removal or optic stalk transection in the cricket Gryllus bimaculatus. J. Insect Physiol. 31: 653–657, 1985.
 994. Tomioka, K., and Y. Chiba. Persistence of circadian ERG rhythm in the cricket with optic tract severed. Naturwissenschaften 69: 395–396, 1982.
 995. Tomioka, K., and Y. Chiba. Effects of nymphal stage optic nerve severance or optic lobe removal on the circadian locomotor rhythm of the cricket, Gryllus bimaculatus. Zool. Sci. 1: 375–382, 1984.
 996. Tomioka, K., and Y. Chiba. Circadian rhythm in the neurally isolated lamina‐medulla complex of the cricket Gryllus bimaculatus. J. Insect Physiol. 32: 747–755, 1986.
 997. Tomioka, K., and Y. Chiba. Characterization of an optic lobe circadian pacemaker by in situ and in vitro recording of neural activity in the cricket, Gryllus bimaculatus. J. Comp. Physiol. 171: 1–8, 1992.
 998. Tomioka, K., Y. Okada, and Y. Chiba. Distribution of circadian photoreceptors in the compound eye of the cricket Gryllus bimaculatus. J. Biol. Rhythms 5: 303–314, 1990.
 999. Tomioka, K., K. Yamada, S. Yokoyama, and Y. Chiba. Mutual interactions between optic lobe circadian pacemakers in the cricket Gryllus bimaculatus. J. Comp. Physiol. [A] 169: 291–298, 1991.
 1000. Toshima, A., K. Honma, and S. Masaki. Factors influencing the seasonal incidence and breaking of diapause in Carposina niponensis Walshingham. Jpn. J. Appl. Entomol. Zool. 5: 260–269, 1961.
 1001. Tripathi, B. K. Circadian control of photoperiodic responses in a female migratory bunting (Emberiza bruniceps). Gen. Comp. Endocrinol. 66: 301–305, 1987.
 1002. Truman, J. W. Circadian rhythms and physiology with special reference to neuroendocrine processes in insects. In: Proceedings of the International Symposium on Circadian Rhythmicity. Wageningen, Netherlands: Pudoc, 1971, p. 111–135.
 1003. Truman, J. W. Physiology of insect ecdysis. I. The eclosion behavior of silkmoths and its hormonal control. J. Exp. Biol. 54: 805–814, 1971.
 1004. Truman, J. W. The role of the brain in the ecdysis rhythm of silkmoths: comparison with the photoperiodic termination of diapause. In: Biochronometry, edited by M. Menaker Washington, DC: National Academy of Sciences, 1971, p. 483–504.
 1005. Truman, J. W. Physiology of insect rhythms. I. Circadian organization of the endocrine events underlying the moulting cycle of larval tobacco hornworms. J. Exp. Biol. 57: 805–820, 1972.
 1006. Truman, J. W. Physiology of insect rhythms. II. The silk moth brain as the location of the biological clock controlling eclosion. J. Comp. Physiol. 81: 99–114, 1972.
 1007. Truman, J. W. Physiology of insect ecdysis. II. The assay and occurrence of the eclosion hormone in the Chinese oak silk‐moth, Antheraea pernyi. Biol. Bull. 114: 200–211, 1973.
 1008. Truman, J. W. Circadian release of a prepatterned neural program in silkmoths. In: The Neurosciences: Third Study Program, edited by F. O. Schmitt and F. G. Worden. Massachusetts Institute of Technology, Cambridge, MA: 1974, p. 525–529.
 1009. Truman, J. W. Physiology of insect rhythms. IV. Role of the brain in the regulation of the flight rhythm of the giant silkmoths. J. Comp. Physiol. 95: 281–296, 1974.
 1010. Truman, J. W. Extraretinal photoreception in insects. Photochem. Photobiol. 23: 215–225, 1976.
 1011. Truman, J. W. Physiological aspects of the two oscillators that regulate timing of eclosion in moths. In: Photoperiodic Regulation of Insect and Molluscan Hormones, edited by R. Porter and G. Collins. London: Pitman, 1984, p. 221–232.
 1012. Truman, J. W. The preparatory behavior rhythms of the moth Manduca sexta: an ecdysteroid‐triggered circadian rhythm that is independent of the brain. J. Comp. Physiol. [A] 155: 521–528, 1984.
 1013. Truman, J. W., and L. M. Riddiford. Neuroendocrine control of ecdysis in silkmoths. Science 167: 1624–1626, 1970.
 1014. Truman, J. W., and P. J. Sokolove. Silkmoth eclosion: hormonal triggering of a centrally programmed pattern of behavior. Science 175: 1491–1493, 1972.
 1015. Turek, F. W. Circadian involvement in the termination of the refractory period in two sparrows. Science 178: 1112–1113, 1972.
 1016. Turek, F. W. Circadian rhythmicity and the initiation of gonadal growth in the sparrow. J. Comp. Physiol. 92: 59–64, 1974.
 1017. Turek, F. W. Effect of melatonin on photic‐independent and photic‐dependent testicular growth in juvenile and adult male hamsters. Biol. Reprod. 20: 1119–1122, 1979.
 1018. Turek, F. W. Effects of stimulated physical activity on the circadian pacemaker of vertebrates. J. Biol. Rhythms 4: 135–147, 1989.
 1019. Turek, F. W., C. Desjardins, and M. Menaker. Melatonin: antigonadal and progonadal effects in male golden hamsters. Science 190: 280–282, 1975.
 1020. Turek, F. W., D. J. Earnest, and J. Swann. Splitting of the circadian rhythm of activity in hamsters. In: Vertebrate Circadian Systems, edited by J. Aschoff, S. Daan, and G. Groos. Berlin: Springer‐Verlag, 1982, p. 203–214.
 1021. Turek, F. W., and S. Losee‐Olson. A benzodiazepine used in the treatment of insomnia phase‐shifts the mammalian circadian clock. Nature 321: 167–168, 1986.
 1022. Turek, F. W., J. P. McMillan, and M. Menaker. Melatonin: effects on the circadian locomotor rhythm of sparrows. Science 194: 1441–1443, 1976.
 1023. Turek, F. W., J. Swann, and D. J. Earnest. Role of the circadian system in reproductive phenomena. Recent Prog. Horm. Res. 40: 143–183, 1984.
 1024. Tyschenko, V. P., and G. F. Tyschenko. The Hamner's effect and its interpretation in relation to the photoperiodic response of insects. Zh. Obshch. Biol. 434: 48–55, 1982.
 1025. Ueck, M. Innervation of the vertebrate pineal. In: The Pineal Gland of Vertebrates Including Man, edited by J. A. Kappers and P. Pévet. New York: Elsevier, 1979, p. 45–87.
 1026. Underwood, H. Retinal and extraretinal photoreceptors mediate entrainment of the circadian locomotor rhythm in lizards. J. Comp. Physiol. 83: 187–222, 1973.
 1027. Underwood, H. Circadian organization in lizards: the role of the pineal organ. Science 195: 587–589, 1977.
 1028. Underwood, H. Photoperiodic time measurement in the male lizard Anolis carolinensis. J. Comp. Physiol. 125: 143–150, 1978.
 1029. Underwood, H. Extraretinal photoreception. In: The Behavioral Significance of Color, edited by E. H. Burt, Jr., New York: Garland, 1979, p. 127–178.
 1030. Underwood, H. Melatonin affects circadian rhythmicity in lizards. J. Comp. Physiol. 130: 317–323, 1979.
 1031. Underwood, H. Photoperiodic photoreception in the male lizard Anolis carolinensis: the eyes are not involved. Comp. Biochem. Physiol. A 67: 191–194, 1980.
 1032. Underwood, H. Circadian organization in the lizard Sceloporus occidentalis: the effect of pinealectomy, blinding, and melatonin. J. Comp. Physiol. 141: 537–547, 1981.
 1033. Underwood, H. Effects of pinealectomy and melatonin on the photoperiodic gonadal response of the male lizard Anolis carolinensis. J. Exp. Zool. 217: 417–422, 1981.
 1034. Underwood, H. Circadian organization in the lizard Anolis carolinensis: a multioscillator system. J. Comp. Physiol. [A] 152: 265–274, 1983.
 1035. Underwood, H. Extraretinal photoreception in the lizard Sceloporus occidentalis: phase response curve. Am. J. Physiol. 248 (Regulatory Integrative Comp. Physiol. 19): R407–R414, 1985.
 1036. Underwood, H. The annual testicular cycle of the lizard Anolis carolinensis: effects of pinealectomy and melatonin. J. Exp. Zool. 233: 235–242, 1985.
 1037. Underwood, H. The pineal and melatonin: regulators of circadian function in lower vertebrates. Experientia 46: 120–128, 1990.
 1038. Underwood, H. The circadian rhythm of thermoregulation in Japanese quail. I. Role of the eyes and pineal. J. Comp. Physiol. [A] 175: 639–653, 1994.
 1039. Underwood, H., R. K. Barrett, and T. Siopes. Melatonin does not link the eyes to the rest of the circadian system in quail: a neural pathway is involved. J. Biol. Rhythms 5: 349–361, 1990.
 1040. Underwood, H., R. K. Barrett, and T. Siopes. The quail's eye: a biological clock. J. Biol. Rhythms 5: 257–265, 1990.
 1041. Underwood, H., S. Binkley, T. Siopes, and K. Mosher. Melatonin rhythms in the eyes, pineal bodies, and blood of Japanese quail (Coturnix coturnix japonica). Gen. Comp. Endocrinol. 56: 70–81, 1984.
 1042. Underwood, H., and M. Calaban. Pineal melatonin rhythms in the lizard Anolis carolinensis: I. Response to light and temperature cycles. J. Biol. Rhythms 2: 179–193, 1987.
 1043. Underwood, H., and M. Calaban. Pineal melatonin rhythms in the lizard Anolis carolinensis: II. Photoreceptive inputs. J. Biol. Rhythms 2: 195–206, 1987.
 1044. Underwood, H., and K. Edmonds. The circadian rhythm of thermoregulation in Japanese quail: III. Effects of melatonin administration. J. Biol. Rhythms 10: 284–298, 1995.
 1045. Underwood, H., and G. A. Gross. Vertebrate circadian rhythms: retinal and extraretinal photoreception. Experientia 38: 1113–1121, 1982.
 1046. Underwood, H., and M. Harless. Entrainment of the activity rhythm of a lizard to melatonin injections. Physiol. Behav. 35: 267–270, 1985.
 1047. Underwood, H., and L. Hyde. A circadian clock measures photoperiodic time in the male lizard Anolis carolinensis. J. Comp. Physiol. [A] 167: 231–243, 1990.
 1048. Underwood, H., and M. Menaker. Extraretinal photoreception in lizards. Photochem. Photobiol. 23: 227–243, 1976.
 1049. Underwood, H., and T. Siopes. Circadian organization in Japanese quail. J. Exp. Zool. 232: 557–566, 1984.
 1050. Underwood, H., T. Siopes, and R. K. Barrett. Does a biological clock reside in the eye of quail? J. Biol. Rhythms 3: 323–331, 1988.
 1051. Underwood, H., J. M. Whitsett, and T. G. O'Brien. Photoperiodic time measurement in the male deer mouse, Peromyscus maniculatus. Biol. Reprod. 32: 947–956, 1985.
 1052. Urasaki, H. Effects of restricted photoperiod and melatonin administration on gonadal weight in the Japanese killifish. J. Endocrinol. 55: 619–620, 1972.
 1053. Urasaki, H. The role of the pineal and eyes in the photoperiodic effect on the gonad of the medaka, Oryzias latipes. Chronobiologia 3: 228–234, 1976.
 1054. Urasaki, H., T. Abe, and S. F. Mawatari. Photoperiodicity of reproduction modulated by extraocular photoreceptive mechanism in Oryzias latipes I. Effect of light restriction on oocyte maturation, ovulation and spawning after removal of bilateral eyes. Bull. Lib. Arts Sci. Course Sch. Med. Nihon Univ. 9: 1–21, 1981.
 1055. Vafopoulou, X., and C.G.H. Steel. Circadian regulation of synthesis of ecdysteroids by prothoracic glands of the insect Rhodnius prolixus: evidence of a dual oscillator system. Gen. Comp. Endocrinol. 83: 27–34, 1991.
 1056. Vafopoulou, X., and C. G. H. Steel. In vitro photosensitivity of ecdysteroid synthesis by prothoracic glands of Rhodnius prolixus. Gen. Comp. Endocrinol. 86: 1–9, 1992.
 1057. van den Pol, A. N. The hypothalamic suprachiasmatic nucleus of rat: intrinsic anatomy. J. Comp. Neurol. 191: 661–702, 1980.
 1058. van den Pol, A. N. Gamma‐aminobutyrate, gastrin releasing peptide, serotonin, somatostatin, and vasopressin: ultrastructural immunocytochemical localization in presynaptic axons in the suprachiasmatic nucleus. Neuroscience 17: 643–659, 1986.
 1059. van den Pol, A. N. The suprachiasmatic nucleus: morphological and cytochemical substrates for cellular interaction. In: Suprachiasmatic Nucleus. The Mind's Clock, edited by D. C. Klein, R. Y. Moore, and S. M. Reppert. New York: Oxford Univ. Press, 1991, p. 17–50.
 1060. van den Pol, A. N., and T. Gorcs. Synaptic relationships between neurons containing vasopressin, gastrin‐releasing peptide, vasoactive intestinal polypeptide, and glutamate decarboxylase immunoreactivity in the suprachiasmatic nucleus: dual ultrastructural immunocytochemistry with gold‐substituted silver peroxidase. J. Comp. Neurol. 252: 507–521, 1986.
 1061. van den Pol, A. N., and K. L. Tsujimoto. Neurotransmitters of the hypothalamic suprachiasmatic nucleus: immunocytochemical analysis of 25 neuronal antigens. Neuroscience 15: 1049–1086, 1985.
 1062. van der Zee, E. A., C. Streefland, A. D. Strosberg, H. Schroder, and P.G.M. Luiten. Colocalization of muscarinic and nicotinic receptors in cholinoceptive neurons of the suprachiasmatic region in young and aged rats. Brain Res. 542: 348–352, 1991.
 1063. Vaněček, J., and H. Illnerová. The regulation of pineal serotonin N‐acetyltransferase activity in newborn rats. Dev. Biol. 68: 287–291, 1979.
 1064. Vaněček, J., and L. Jansky. Short days induce changes in specific melatonin binding in hamster median eminence and anterior pituitary. Brain Res. 477: 387–398, 1989.
 1065. Vaněček, J., E. Kosar, and J. Vorlicek. Daily changes in melatonin binding sites and the effect of castration. Mol. Cell. Endocrinol. 73: 165–170, 1990.
 1066. Vaněček, J., A. Pavlik, and H. Illnerova. Hypothalamic melatonin receptor sites revealed by autoradiography. Brain Res. 435: 359–362, 1987.
 1067. Vaněček, J., and L. Vollrath. Melatonin inhibits cyclic AMP and cyclic GMP accumulation in the rat pituitary. Brain Res. 505: 157–159, 1989.
 1068. van Houten, Y. M., and A. Veerman. Photoperiodism and thermoperiodism in the predatory mite Amblyseius potentillae are probably based on the same mechanism. J. Comp. Physiol. [A] 167: 210–209, 1990.
 1069. van Reeth, O., D. Hinch, J. M. Tecco, and F. W. Turek. The effects of short periods of immobilization on the hamster circadian clock. Brain Res. 545: 208–214, 1991.
 1070. van Reeth, O., and F. W. Turek. Stimulated activity mediates phase shifts in the hamster circadian clock induced by dark pulses or benzodiazepines. Nature 339: 49–51, 1989.
 1071. van Veen, T., H.‐G. Hartwig, and K. Muller. Light‐dependent motor activity and photonegative behavior in the eel (Anguilla anguilla L.). Evidence for extraretinal and extrapineal photo‐reception. J. Comp. Physiol. 111: 209–219, 1976.
 1072. van Zon, A. Q., W. P. J. Overmeer, and A. Veerman. Carotenoids function in photoperiodic induction of diapause in a predacious mite. Science 213: 1131–1133, 1981.
 1073. Vaughan, M. K. Arginine vasotocin and vertebrate reproduction. In: The Pineal Gland. Reproductive Effects, edited by R. J. Reiter. Boca Raton, FL: CRC, 1981, vol. II, p. 125–164.
 1074. Vaughan, M. K. Pineal peptides: an overview. In: The Pineal Gland, edited by R. J. Reiter. New York: Raven, 1984, p. 39–82.
 1075. Vaz Nunes, M., and J. Hardie. An instantly damping oscillator model for photoperiodic time measurement in the aphid Aphis fabae. J. Insect Physiol. 33: 831–841, 1987.
 1076. Vaz Nunes, M., and J. Hardie. “Bistability” experiments and photoperiodic time measurement in the aphid Aphis fabae. J. Insect Physiol. 33: 831–841, 1989.
 1077. Vaz Nunes, M., N.A.P. Kenney, and D. S. Saunders. The photoperiodic clock in the blowfly Calliphora vicina. J. Insect Physiol. 36: 61–67, 1990.
 1078. Vaz Nunes, M., and A. Veerman. Photoperiodic time measurement in spider mites. I. Development of a two interval timers model. J. Comp. Physiol. 134: 203–217, 1979.
 1079. Vaz Nunes, M., and A. Veerman. Photoperiodic time measurement in spider mites. II. Effects of skeleton photoperiods. J. Comp. Physiol. 134: 219–226, 1979.
 1080. Vaz Nunes, M., and A. Veerman. Photoperiodic time measurement in the spider mite Tetranychus urticae: a novel concept. J. Insect Physiol. 28: 1041–1053, 1982.
 1081. Veerman, A. Functional involvement of carotenoids in photoperiodic induction of diapause in the spider mite, Tetranychus urticae. Physiol. Entomol. 5: 291–300, 1980.
 1082. Veerman, A. Diapause. In: Spider Mites. Their Biology, Natural Enemies and Control, edited by W. Helle and M. W. Sabelis. Amsterdam: Elsevier, 1985, vol. 1A, p. 279–316.
 1083. Veerman, A., and W. Helle. Evidence for the functional involvement of carotenoids in the photoperiodic reaction of spider mites. Nature 275: 234, 1978.
 1084. Veerman, A., and W. M. Herrebout. Photoperiodic response curve for Yponomeuta vigintipunctatus (retz.) (Lepidoptera: Yponomeutidae). Neth. J. Zool. 32: 117–122, 1982.
 1085. Veerman, A., W.P.J. Overmeer, A. Q. van Zon, J. M. de Boer, E. R. de Waard, and H. O. Huisman. Vitamin A is essential for photoperiodic induction of diapause in an eyeless mite. Nature 302: 248–249, 1983.
 1086. Veerman, A., M. E. Slagt, M.F.J. Alderlieste, and R. L. Veenendaal. Photoperiodic induction of diapause in an insect is vitamin A dependent. Experientia 41: 1194–1195, 1985.
 1087. Veerman, A., and M. Vaz Nunes. Orcadian rhythmicity participates in the photoperiodic determination of diapause in spider mites. Nature 287: 140–141, 1980.
 1088. Veerman, A., and M. Vaz Nunes. Photoperiod reception in spider mites: photoreceptor, clock, and counter. In: Photoperiodic Regulation of Insect and Molluscan Hormones. Ciba Foundation Symposium 104, edited by R. Porter and G. M. Collins. London: Pitman, 1984, p. 48–59.
 1089. Velazquez, E., A. I. Esquifino, J. A. Zueco, J.M.R. Albusac, and E. Blazquez. Evidence that circadian variations of circulating melatonin levels in fetal and suckling rats are dependent on maternal melatonin transfer. Neuroendocrinology 55: 321–326, 1992.
 1090. Vepsalainen, K. Lengthening of illumination period is a factor in averting diapause. Nature 247: 385–386, 1974.
 1091. Viswanathan, N. Presence–absence of the mother and not light–darkness are the zeitgeber for the circadian rhythm of newborn mice. Experientia 45: 383–385, 1989.
 1092. Viswanathan, N., and M. K. Chandrashekaran. Cycles of presence and absence of mother mouse entrain the circadian clock of pups. Nature 317: 530–531, 1985.
 1093. Viswanathan, N., and M. K. Chandrashekaran. Continuous light abolishes the maternal entrainment of the circadian activity rhythm of the pups in the field mouse. Experientia 43: 576–578, 1987.
 1094. Vivien‐Roels, B., J. Arendt, and J. Bradtke. Circadian and circannual fluctuations of pineal indoleamines (serotonin and melatonin) in Testudo hermanni Gmelin (Reptilia, Chelonia). I. Under natural conditions of photoperiod and temperature. Gen. Comp. Endocrinol. 37: 197–210, 1979.
 1095. Vodicnik, M. J., J. Olcese, G. Delahunty, and V. de Vlaming. The effects of blinding, pinealectomy and exposure to constant dark conditions on gonadal activity in the female goldfish, Carassius auratus. Environ. Biol. Fish. 4: 173–177, 1979.
 1096. von der Hyde, F., A. Wilkens, and L. Rensing. The effects of temperature on the circadian rhythms of flashing and glow in Gonyaulax polydrea: are the two rhythms controlled by two oscillators? J. Biol. Rhythms 7: 115–124, 1992.
 1097. von Frisch, K. The Dancing Bees. New York: Harcourt, Brace and World, 1953.
 1098. Wada, M. Photoperiodic control of LH secretion in Japanese quail with special reference to the photoinducible phase. Gen. Comp. Endocrinol. 39: 141–149, 1979.
 1099. Wada, M. Photoinducible phase for gonadotropin secretion entrained to dawn in Japanese quail. Gen. Comp. Endocrinol. 43: 227–233, 1981.
 1100. Waddel, B., R. D. Lewis, and W. Engelman. Localization of the circadian pacemakers of Hemideina thoracica (Orthoptera; Stenopelmatidae). J. Biol. Rhythms 5: 131–140, 1990.
 1101. Wade, G. N. Sex hormones, regulatory behaviors and body weight. In: Advances in the Study of Behavior, edited by J. S. Rosenblatt, R. H. Hinde, E. Shaw, and C. G. Beer. New York: Academic, 1976, vol. 6, p. 201–276.
 1102. Wade, G. N., and T. J. Bartness. Seasonal obesity in Syrian hamsters: effects of age, diet, photoperiod, and melatonin. Am. J. Physiol. 247 (Regulatory Integrative Comp. Physiol. 18): R328–R334, 1984.
 1103. Wade, G. N., and J. M. Gray. Gonadal effects on food intake and adiposity: a metabolic hypothesis. Physiol. Behav. 22: 583–593, 1979.
 1104. Wahlström, G. Experimental modifications of the internal clock in the canary, studied by self‐selection of light and darkness. In: Circadian Clocks, edited by J. Aschoff. Amsterdam: North‐Holland, 1965, p. 324–328.
 1105. Walker, T. J. Wing dimorphism in Gryllus rubens (Orthoptera: Gryllidae). Ann. Entomol. Soc. Am. 80: 547–560, 1987.
 1106. Walsh, S. W., C. A. Ducsay, and M. J. Novy. Circadian hormonal interactions among the mother, fetus and amniotic fluid. Am. J. Obstet. Gynecol. 150: 745–753, 1984.
 1107. Wassmer, G. T. Termination and Induction of Diapause of the European Corn Borer (Ostrinia nubilalis) under Semi‐Natural and Natural Conditions. Newark: Univ. of Delaware, 1990. Dissertation.
 1108. Wassmer, G. T., W. Cain, and T. L. Page. Photoperiodic regulation of hemolymph protein in the woodroach Parcoblatta pennsylvanica. J. Insect Physiol, (in press), 1996.
 1109. Wassmer, G. T., and T. L. Page. Photoperiodic time measurement and a graded response in a cockroach. J. Biol. Rhythms 8: 47–56, 1993.
 1110. Watson‐Whitmyre, M., and M. H. Stetson. Simulation of peak melatonin release restores sensitivity to evening melatonin injections in pinealectomized hamsters. Endocrinology 112: 763–765, 1983.
 1111. Watson‐Whitmyre, M., and M. H. Stetson. Reproductive refractoriness in hamsters: environmental and endocrine etiologies. In: Processing of Environmental Information in Vertebrates, edited by M. H. Stetson. New York: Springer‐Verlag, 1988, p. 219–249.
 1112. Watt, W. B. Adaptive significance of pigment polymorphisms in Colias butterflies. I. Variation of melanin pigment in relation to thermoregulation. Evolution 2: 437–458, 1968.
 1113. Watt, W. B. Adaptive significance of pigment polymorphisms in Colias butterflies. II. Thermoregulation and photoperiodically controlled melanin variation in Colias eurytheme. Proc. Natl. Acad. Sci. U.S.A. 63: 767–774, 1969.
 1114. Wayne, N. L., B. Malpaux, and F. J. Karsch. How does melatonin code for day length in the ewe: duration of nocturnal melatonin release or coincidence of melatonin with a light‐entrained sensitive period? Biol. Reprod. 39: 66–75, 1988.
 1115. Weaver, D. R., L. L. Carlson, and S. M. Reppert. Melatonin receptors and signal transduction in melatonin‐sensitive and melatonin‐insensitive populations of white‐footed mice (Peromyscus leucopus). Brain Res. 506: 353–357, 1990.
 1116. Weaver, D. R., J. T. Keohan, and S. M. Reppert. Definition of a prenatal sensitive period for maternal‐fetal communication of day length. Am. J. Physiol. 253 (Endocrinol. Metab. 16): E701–E704, 1987.
 1117. Weaver, D. R., and S. M. Reppert. Maternal melatonin communicates daylength to the fetus in Djungarian hamsters. Endocrinology 119: 2861–2863, 1986.
 1118. Weaver, D. R., and S. M. Reppert. Maternal–fetal communication of circadian phase in a precocious rodent, the spiny mouse. Am. J. Physiol. 253 (Endocrinol. Metab. 16): E401–E409, 1987.
 1119. Weaver, D. R., and S. M. Reppert. The influence of light on the mammalian fetus. In: Processing of Environmental Information in Vertebrates, edited by M. H. Stetson. New York: Springer‐Verlag, 1988, p. 149–177.
 1120. Weaver, D. R., and S. M. Reppert. Melatonin receptors are present in the ferret pars tuberalis and pars distalis, but not in brain. Endocrinology 127: 2607–2609, 1990.
 1121. Weaver, D. R., S. A. Rivkees, and S. M. Reppert. Localization and characterization of melatonin receptors in rodent brain by in vitro autoradiography. J. Neurosci. 9: 2581–2590, 1989.
 1122. Weber, F. Postmolt cuticle growth in a cockroach: in vitro deposition of multilamellate and circadian‐like layered endocuticle. Experientia 41: 398–400, 1985.
 1123. Webster, J. R., J. M. Suttie, and L. D. Corson. Effects of melatonin implants on reproductive seasonality of male red deer (Cervus elaphus). J. Reprod. Fertil. 92: 1–11, 1991.
 1124. Weigand, S. J., and D. M. Gash. Organization and efferent connections of transplanted suprachiasmatic nuclei. J. Comp. Neurol. 267: 562–579, 1988.
 1125. Welsh, D. K., G. S. Richardson, and W. C. Dement. Effects of running wheel availability on the circadian pattern of sleep and wakefulness in the mouse. Sleep Res. 14: 316, 1985.
 1126. Welsh, D. K., G. S. Richardson, and W. C. Dement. Effect of running wheel availability on circadian patterns of sleep and wakefulness in mice. Physiol. Behav. 43: 771–777, 1988.
 1127. Wenger, D., H. Biebach, and J. R. Krebs. Free‐running circadian rhythm of a learned feeding pattern in starlings. Naturwissenschaften 78: 87–89, 1991.
 1128. Wever, R. T. The Circadian System of Man. New York: Springer‐Verlag, 1979.
 1129. Wheeler, W. M. A contribution to insect embryology. J. Morphol. 8: 1–160, 1893.
 1130. Whitesell, J. J., and T. J. Walker. Photoperiodically determined dimorphic calling songs in a katydid. Nature 274: 887–888, 1978.
 1131. Whitsett, J. M., J. Cherry, and H. Underwood. Involvement of the circadian system in photoperiodic control of pubertal development in female deer mice, Peromyscus maniculatus. Experientia 40: 887–888, 1984.
 1132. Whitsett, J. M., H. Underwood, and J. Cherry. Photoperiodic stimulation of pubertal development in male deer mice: involvement of the circadian system. Biol. Reprod. 28: 652–656, 1983.
 1133. Whittier, J. M., and D. Crews. Seasonal reproduction: patterns and control. In: Hormones and Reproduction in Fishes, Amphibians and Reptiles, edited by D. Norris and R. E. Jones. New York: Plenum, 1987, p. 385–409.
 1134. Wiechmann, A. F. Melatonin: parallels in pineal gland and retina. Exp. Eye Res. 42: 507–527, 1986.
 1135. Wiechmann, A. F., and J. G. Hollyfield. HIOMT‐like immunoreactivity in the vertebrate retina: a species comparison. Exp. Eye Res. 49: 1079–1095, 1989.
 1136. Wiedenmann, G. Splitting in a circadian activity rhythm: the expression of bilaterally paired oscillators. J. Comp. Physiol. 150: 51–60, 1983.
 1137. Wiedenmann, G., and W. Loher. Circadian control of singing in crickets: two different pacemakers for early‐evening and before‐dawn activity. J. Insect Physiol. 30: 145–151, 1984.
 1138. Wiedenmann, G., R. Lukat, and F. Weber. Cyclic layer deposition in the cockroach endocuticle: a circadian rhythm? J. Insect Physiol. 32: 1019–1027, 1986.
 1139. Williams, C. M. Photoperiodism and the endocrine aspects of insect diapause. Symp. Soc. Exp. Biol. 23: 285–300, 1969.
 1140. Williams, C. M., and P. L. Adkisson. Physiology of insect diapause. XIV. An endocrine mechanism for the photoperiodic control of pupal diapause in the oak silkworm, Antheraea pernyi. Biol. Bull. Marine Biol. Lab. Woods Hole 127: 511–525, 1964.
 1141. Wills, S. A., T. L. Page, and C. Colwell. Circadian rhythms in the electroretinogram of the cockroach. J. Biol. Rhythms 1: 25–37, 1985.
 1142. Wilson, F. E. Extraocular control of photorefractoriness in American tree sparrows (Spizella arborea). Biol. Reprod. 41: 111–116, 1989.
 1143. Wilson, F. E. Extraocular control of seasonal reproduction in female tree sparrows (Spizella arborea). Gen. Comp. Endocrinol. 77: 397–402, 1990.
 1144. Wilson, F. E. Neither retinal nor pineal photoreceptors mediate photoperiodic control of seasonal reproduction in American tree sparrows (Spizella arborea). J. Exp. Zool. 259: 117–127, 1991.
 1145. Wilson, M. E., and T. P. Gordon. Short‐day melatonin pattern advances puberty in seasonally breeding rhesus monkeys (Macaca mulatto). J. Reprod. Fertil. 86: 435–444, 1989.
 1146. Wingfield, J. C. Environmental and endocrine control of reproduction in the song sparrow, Melospiza melodia II. Agonistic interactions as environmental information stimulating secretion of testosterone. Gen. Comp. Endocrinol. 56: 417–424, 1984.
 1147. Wingfield, J. C. Influence of weather on reproduction. J. Exp. Zool. 232: 589–594, 1984.
 1148. Wingfield, J. C., and D. S. Farner. Control of seasonal reproduction in temperate zone birds. Prog. Reprod. Biol. 5: 62–101, 1980.
 1149. Woodfill, C.J.I., J. E. Robinson, B. Malpaux, and F. J. Karsch. Synchronization of the circannual reproductive rhythm of the ewe by discrete photoperiodic signals. Biol. Reprod. 45: 110–121, 1991.
 1150. Woolum, J., and F. Strumwasser. The differential effects of ionizing radiation on the circadian oscillator and other functions in the eye of Aplysia. Proc. Natl. Acad. Sci. U.S.A. 77: 5542–5546, 1980.
 1151. Yamada, N., K. Shimoda, K. Ohi, S. Takahashi, and K. Takahashi. Free‐access to a running wheel shortens the period of free‐running rhythm in blinded rats. Physiol. Behav. 42: 87–91, 1988.
 1152. Yamada, N., K. Shimoda, K. Takahashi, and S. Takahashi. Relationship between free‐running period and motor activity in blinded rats. Brain Res. Bull. 25: 115–119, 1990.
 1153. Yamashita, O., and K. Hasegawa. Embryonic diapause. In: Comprehensive Insect Physiology, Biochemistry, and Pharmacology, edited by G. A. Kerkut and L. I. Gilbert. Oxford: Pergamon, 1985, p. 407–434.
 1154. Yellon, S. M., E. L. Bittman, M. N. Lehman, D. H. Olster, J. E. Robinson, and F. J. Karsch. Importance of duration of nocturnal melatonin secretion in determining the reproductive response to inductive photoperiod in the ewe. Biol. Reprod. 32: 523–529, 1985.
 1155. Yokoyama, K., and D. S. Farner. Photoperiodic responses in bilaterally enucleated female white‐crowned sparrows, Zonotrichia leucophrys gambelii. Gen. Comp. Endocrinol. 30: 528–533, 1976.
 1156. Yokoyama, K., A. Oksche, T. R. Darden, and D. S. Farner. The sites of encephalic photoreception in photoperiodic induction of the growth of the testes in the white‐crowned sparrow, Zonotrichia leucophrys gambelii. Cell Tissue Res. 189: 441–467, 1978.
 1157. Yuan, H., and S. F. Pang. [125I] Melatonin binding sites in membrane preparations of quail brain: characteristics and diurnal variations. Acta Endocrinol. 122: 633–639, 1990.
 1158. Yuan, H., and S. F. Pang. [125I] Iodomelatonin‐binding sites in the pigeon brain: binding characteristics, regional distribution and diurnal variation. J. Endocrinol. 128: 475–482, 1991.
 1159. Yuan, H., F. Tang, and S. F. Pang. Binding characteristics, regional distribution and diurnal variation of [125I]‐iodomelatonin binding sites in the chicken brain. J. Pineal Res. 9: 179–191, 1990.
 1160. Zachmann, A., S.C.M. Knijff, V. Bolliet, and M. A. Ali. Effects of temperature cycles and photoperiod on rhythmic melatonin secretion from the pineal organ of a teleost (Catostomus commersoni) in vitro. Neuroendocrinal. Lett. 13: 325–330, 1991.
 1161. Zatz, M., and M. A. Herkenham. Intraventricular carbachol mimics the phase shifting effects of light on the circadian rhythm of wheel‐running activity. Brain Res. 212: 234–238, 1981.
 1162. Zawilska, J. B., and J. Z. Nowak. Regulatory mechanisms in melatonin biosynthesis in retina. Neurochem. Int. 20: 23–36, 1992.
 1163. Zeman, M. Ontogeny of N‐acetyltransferase activity rhythm in pineal gland of chick embryo. Comp. Biochem. Physiol. A 97: 175–178, 1990.
 1164. Zielinski, W. J. Circadian rhythms of small carnivores and the effect of restricted feeding on daily activity. Physiol. Behav. 38: 613–620, 1986.
 1165. Zimmerman, N. H., and M. Menaker. The pineal gland: a pacemaker within the circadian system of the house sparrow. Proc. Natl. Acad. Sci. U.S.A. 76: 999–1003, 1979.
 1166. Zimmerman, W. F., and T. H. Goldsmith. Photosensitivity of the circadian rhythm and of visual receptors in carotenoid depleted Drosophila. Science 171: 1167–1168, 1971.
 1167. Zimmerman, W. F., and D. Ives. Some photophysical aspects of circadian rhythmicity in Drosophila. In: Biochronometry, edited by M. Menaker. Washington, DC: National Academy of Sciences, 1971, p. 381–391.
 1168. Zisapel, N., I. Nir, and M. Laudon. Circadian variations in melatonin‐binding sites in discrete areas of the male rat brain. Fed. Eur. Biochem. Soc. Lett. 232: 172–176, 1988.
 1169. Zisapel, N., M. Shaharabani, and M. Laudon. Regulation of melatonin's activity in the female rat brain by estradiol: effects on neurotransmitter release and on iodomelatonin binding sites. Neuroendocrinology 46: 207–216, 1987.
 1170. Zoeller, R. T., N. F. Licklider, E. R. Anderson, and H. E. Albers. Cellular levels of messenger RNAs encoding VIP/PHI and gastrin releasing peptide (GRP, bombesin) exhibit different 24 hr rhythms in the rat SCN. Prog. Endocrinol. Soc. 72: 336, 1990.
 1171. Zucker, I. Pineal gland influences period of circannual rhythms of ground squirrels. Am. J. Physiol. 249 (Regulatory Integrative Comp. Physiol. 20): R111–R115, 1985.
 1172. Zucker, I., M. Boshes, and J. Dark. Suprachiasmatic nuclei influence circannual and circadian rhythms of ground squirrels. Am. J. Physiol. 244 (Regulatory Integrative Comp. Physiol. 15): R472–R480, 1983.
 1173. Zucker, I., K. M. Fitzgerald, and L. P. Morin. Sex differentiation of the circadian system in the golden hamster. Am. J. Physiol. 238 (Regulatory Integrative Comp. Physiol. 9): R97–R101, 1980.
 1174. Zucker, I., T. M. Lee, and J. Dark. The suprachiasmatic nucleus and annual rhythms of mammals. In: Suprachiasmatic Nucleus. The Mind's Clock, edited by D. C. Klein, R. Y. Moore, and S. M. Reppert. New York: Oxford Univ. Press, 1991, p. 246–259.
 1175. Zucker, I., and P. Licht. Circannual and seasonal variations in plasma luteinizing hormone levels of ovariectomized ground squirrels (Spermophilus lateralis). Biol. Reprod. 28: 178–185, 1983.
 1176. Zucker, I., and P. Licht. Seasonal variations in plasma luteinizing hormone levels of gonadectomized male ground squirrels (Spermophilus lateralis). Biol. Reprod. 29: 278–285, 1983.
 1177. Zwicky, K. T. Behavioral aspects of the extraocular light sense of Urodacus, a scorpion. Experientia 26: 747–748, 1970.

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Article Title: Daily and Seasonal Rhythms
 

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Herbert A. Underwood, Gary T. Wassmer, Terry L. Page. Daily and Seasonal Rhythms. Compr Physiol 2011, Supplement 30: Handbook of Physiology, Comparative Physiology: 1653-1763. First published in print 1997. doi: 10.1002/cphy.cp130224