THE VISUAL PIGMENTS AND THEIR PHOTOPRODUCTS 



absorption band of the product is then located farthest from the 

 band of the parent pigment. The 'overlap' is minimal and conse- 

 quently the upper and lower portions of the difference spectrum 

 (Fig. 2.13) are at their nearest approximation to the true density 

 spectra of parent and product respectively. The Amax of an 'alkaline' 

 difference spectrum is displaced not more than 2 or 3 m/u above that 

 for the pure visual pigment (cf. Fig. 2.6). 



REFERENCES 



Arden, G. B. (1954). The dark reactions in visual cell suspensions. 



/. Physiol., 123, 386-395. 

 Berger, p. and Segal, J. (1950a). Le spectre d'absorption de I'orange 



transitoire retinien. C.R. Soc. bioL, 144, 478-^79. 

 Berger, P. and Segal, J. (1950b). La photolyse fractionnee du pourpre 



retinien. Comp. rend., 230, 1903-1905. 

 Bliss, A. F. (1948). The mechanism of retinal vitamin A formation. 



J. biol. Chem., Ill, 165-178. 

 Boll, F. (1876). Zur Anatomic und Physiologic der Retina. Monatsber. 



Akad. Wiss. Berlin, 1^2>-m. 

 Broda, E. E. and Goodeve, C. F. (1941). The behaviour of visual purple 



at low temperature. Proc. roy. Soc. A., 179, 151-159. 

 Chase, A. M. (1936). Anomalies in the absorption spectrum and bleaching 



kinetics of visual purple. J. gen. Physiol., 19, 577-599. 

 Collins, F. D. and Morton, R. A. (1950a). Studies on rhodopsin. 1. 



Methods of extraction and the absorption spectrum. Biochem. /., 47, 



3-10. 

 Collins, F. D. and Morton, R. A. (1950b). Studies on rhodopsin. 2. 



Indicator yellow. Biochem. J., 47, 10-17. 

 Collins, F. D. and Morton, R. A. (1950c). Studies in rhodopsin. 3. 



Rhodopsin and transient orange. Biochem. J., 47, 18-24. 

 CREScrrELLi, F. and Dartnall, H. J. A. (1954). A photosensitive pigment 



of the carp retina. /. Physiol., 125, 607-627. 

 Dartnall, H. J. A. (1952). Visual pigment 467, a photosensitive pigment 



present in tench retinae. J. Physiol., 116, 257-289. 

 Edisbury, J. R., Morton, R. A. and Simpkins, G. W. (1937). A possible 



vitamin Ag. Nature, Lond., 140, 234. 

 EwALD, A. and Kuhne, W. (1878). Untersuchungen iiber den Sehpurpur. 



Unters. physiol. Inst. Heidelberg., 1, 139-218, 248-290, 370-455. 

 Fridericia, L. S. and Holm, E. (1925). Experimental contribution to the 



study of the relation between night blindness and malnutrition. Influ- 

 ence of deficiency of fat-soluble A-vitamin in the diet on the visual 



purple in the eyes of rats. Am. J. Physiol, 73, 63-78. 

 Garten, S. (1907). Die Veranderungen der Netzhaut durch Licht. 



Handb. d.ges. Augenheilk., 3, Chap. 12, 1-250. 

 Holm, E. (1922). Sur la decoloration du pourpre visuel. C.R. Soc. BioL, 



87, 465-466. 



57 



