xvi CONTENTS 



Additional Remarks on the Role of the Endogenous Diurnal 



Periodicity in Photoperiodism, by Erwin Biinning 531 



Diurnal Changes in Pigment Content and in the Photoperi- 

 odic Efficiency of Red and Far Red, by Erwin Biinning 537 



Induction of Phase Shift in Cellular Rhythmicity by Far 

 Ultraviolet and Its Restoration by Visible Radiant Energy, 

 by Charles F. Ehret 541 



The Periodic Aspect of Photoperiodism and Photoperiodicity, 

 by Frits W. Went 551 



Section VIII Photoperiodism in the Invertebrates 



The Gonyaulax Clock, by /. Woodland Hastings and Beatrice 



M. Sweeney 567 



Photoperiodism in Insects and Mites, by ^. D. Lees 585 



Photoperiodic Control of Diapause in the Pitcher-Plant 

 Midge, Metriocnemiis knabi, by Oscar H. Paris, Jr., and 

 Charles E. Jenner 60 1 



Reproductive Cycles of Some West Coast Invertebrates, by 

 Arthur C. Giese 625 



Section IX Photoperiodism in the Vertebrates 



Vertebrate Photostimulation, by William S. Bullough 641 



Photoperiodism in Fishes in Relation to the Annual Sexual 



Cycle, by Robert Whiting Harrington, Jr. 651 



Photoperiodism in Reptiles, by George A. Bartholomew 669 



Section X Photoperiodic Control of Reproduction 

 and Migration in Birds 



The Role of Light and Darkness in the Regulation of Spring 

 Migration and Reproductive Cycles in Birds, by Albert 

 Wolf son 679 



Photoperiodic Control of Annual Gonadal Cycles in Birds, 



by Donald S. Earner 111 



