THE VISUAL PIGMENTS 



Visual purple (Rhodopsin) 

 absorption spectra of, 1 6 

 astacene, comparison with, 103 

 bleaching/time curve in retina, 199 

 bleaching/time curve in solution, 



67 

 cattle, 48^9, 53, 84, 97, 148 

 chromophore carrier weight of, 



90-92 

 chromophore of, 99-103 

 cycle (Wald's) of, 30-31 

 density in human eye of, 203 

 density in situ of, 1 89 

 density spectra of, 17, 22, 33-34, 37, 



97 

 difference spectra of, 22, 29, 176- 



177, 184, 193, 199 

 discovery of, 25 

 distribution of, 37 

 extractants for, 9-1 1 

 extraction procedures for, 11-13 

 extinction coefficient of, 82-84 

 formulae proposed for, 108, 120, 123 

 human, 6, 22-23, 99, 203 

 indicator yellow, relation to, 54 

 in excised retina, 186-189 

 in mammals, birds and amphibians, 



29 

 in marine fish, 33- 34 

 in visual cells, 182-185 

 internal energy of, 86-90 

 lumi-rhodospin, relation to, 54 

 meta-rhodopsin, relation to, 54 

 molecular weight of, 92-94 

 other pigments, comparison with, 



175-177 

 ovoverdin, comparison with, 123 

 photochemistry of, 60-84 

 photoproducts of, 41-57 

 photosensitivity maximum, 77, 84 

 photosensitivity, variation of with 



wavelength, 77-78, 97 

 protein moiety of, 98-99 

 quantum efficiency of bleaching of, 



77, 79-82 

 regeneration of, 79-82, 114-118, 



146-147 

 regeneration spectrum of, in retina, 



200 

 regeneration/time curve in retina, 



199 

 retinenei, relation to, 31, 54 

 SH- groups and, 118-120 

 structure of, 96-124 



synthesis of, from weo-retinenei by 



145-146 

 synthesis of, from vitamin Aj, 126, 



135-137 

 thermochemistry of, 84-90 

 titration of, 119 



transient orange, relation to, 54 

 vitamin Aj, relation to, 31, 54 

 Visual violet (see Porphyropsin) 

 Visual white or Leucopsin (see also 



Vitamin A), 26-27, 42 

 Visual yellow or Xanthopsin (see also 



Indicator yellow and Retinene), 



26, 42-^3, 51 

 Vitamin A (Vitamin Aj) 

 and the rhodopsin-porphyropsin 



theory, 32-37 

 crystalline (all trans), 126, 135-137 

 density spectrum in chloroform, 33 

 distribution in livers, retinae and 



other eye tissues, 35-36 

 formula of, 99-100 

 in fish, 36 



isomers of, 135-137 

 retinene, relation to, 30-31, 54, 



103-104 

 tests for, 30 



visual purple, relation to, 30-31, 54 

 Vitamin Aj 

 and cyanopsin, 153 

 and the rhodopsin-porphyropsin 



theory, 32-37 

 density spectrum in chloroform, 33 

 distribution of, in livers, retinae and 



other eye tissues, 35-36 

 formula of, 100 

 in fish, 36 



porphyropsin, relation to, 32, 38-41 

 retineneg, relation to, 31-32 

 tests for, 32 

 Vitreous humour, 1-2, 9 



Wavelength of maximum absorption, 

 eff'ect of impurities on, 39-41 



White perch (Morone americana), 

 45-47 



White perch {Perca flavescens), 30, 36 



Whiting (Merlucius bilinearis), 36 



Xanthopsin (visual yellow), see also 



indicator yellow, 26 

 Xenopus laevis, 5 



Zein, reaction with retinencj, 106 



216 



