I 



888 



SUBJECT INDEX 



Darkness, continuous (Continued) 

 effect on Mocrosiphiim, 621 

 effect on Metatetranychus, 62 1 

 effect on Metriocnemus knabi, 



621 

 photoperiodic response of birds 



to, 621 

 response of Metriocnemus 

 knabi to, 621 

 effect on fish maturity, 655, 657, 

 660 

 Dark period 

 inductive 



light interruption of, 390 

 light interruption of, 751, 752, 

 754 

 Day length; see also Photoperiod 

 combined effects with tempera- 

 ture, 656, 659-662 

 at different phases of maturity, 



661,662 

 at different seasons, 660, 661 

 on fish sex cycle, 656, 659, 662 

 on oogenesis, 656, 660 

 on spermatogenesis, 656, 660 

 critical, 245, 246, 248, 249 

 cycle, 441-444 

 duration of, 447 

 effect on flowering, 442, 451 

 effect on various modes of manip- 

 ulation of fish sex cycle, 660, 

 661,663 

 extended, 401 

 Day-neutral plants, 245, 406 

 Deoxyribonucleic acid ( DNA ) , 4 1 1 , 



825, 826, 847, 852 

 Desoxycorticosterone, 827 

 Diapause, 586-588, 602 



in Metriocnemus knabi, 615, 617, 

 618 

 Diapause, facultative, 602 

 Diataraxia 



critical photoperiod of, 618, 621 



effect of temperature on the photo- 

 periodic response of, 618 

 2,4-Dichlorophenoxyacetic acid 



(2,4-D),384, 385 

 2,2-Dichloropropionic acid (Dala- 



pon),384, 385 

 Diffusion 



of light by opal glass, 23 

 Digitonine 



influence on diurnal periodicity, 

 519 

 2,4-Dinitrophenol, 384, 385 

 Dinoflagellates 



flashing of, 567 



glowof, 570, 571 



light emission by, 567 



luminescence of, 567 



marine, 567 

 Dipt era 



photoperiodism in, 632 

 Dispersion 



anomalous, 19 

 Diurnal periodicity 



and chilling, 520 



and colchicine, 519 



and digitonine, 519 



and heredity, 510 



andlight, 519, 522,523 



and photoperiodism, 522, 531, 

 533 



and poisons, 519 



and temperature, 513 



and urethane, 5 1 9, 520 



evocation of, 522, 523 



in activity of movements, 508, 

 509,513,515 



in bioluminescence, 508 



in chlorophyll content, 537, 538 



in emergence of insects, 507 



in enzyme activity, 507 



in growth rate, 507 



in leaf movements, 513, 515, 517, 

 519,520,533 



