47 6 



THE QUARTERLY REVIEW OF BIOLOGY 



tissues, and where carotin is found, partic- 

 ularly carotin exposed to sunlight, there 

 the vitamine may be expected to be present 

 also. 



Fat soluble vitamine has been shown to 

 be intimately associated with yellow 

 pigment. Maize, carrots and sweet pota- 

 toes which are highly impregnated with 

 the yellow pigment were found to supple- 

 ment successfully rations known to be 

 deficient in fat soluble vitamine. Roots 

 not pigmented were found to be impotent. 

 Butter rich in pigment and also oils con- 

 taining the yellow pigment show a con- 

 siderable fat-soluble vitamine content. In 

 the case of the leafy parts of plants the 

 growth promoting property is associated 

 with the yellow pigments, though here 

 the yellow pigments are masked by the 

 chlorophyll. 



Regarding the relation of vitamines to 

 lipochromes, Palmer says that he dis- 

 missed the possibility of any such relation 

 as the result of experiments carried out in 

 the winter of 191 6-17, in which normal 

 chickens were raised to maturity on 

 carotinoid-free rations. Drummond in 

 1919 reported the failure of pure crystalline 

 carotin to improve the condition of albino 

 rats suffering from vitamine A deficiency, 

 while at the same time Steenbock, Bout- 

 well and Kent were suggesting that the 

 two were at least associated in some way. 

 Steenbock and his associates have pub- 

 lished a series of papers showing that a 

 rather close correlation exists between 

 carotinoid pigmentation and vitamin A. 

 Steenbock and Boutwell's results show 

 that highly colored extracts do not 

 exhibit the vitamine activity which would 

 be expected if vitamine A were a carot- 

 inoid. Steenbock has been forced to 

 abandon his position that the two sub- 

 stances may be identical and to admit that 

 their "coincident occurrence in nature 



might be due to physiological deter- 

 mination, pure and simple." 



The lack of correlation between pigmen- 

 tation and vitamine content of animal 

 fats was first pointed out by Drummond 

 and Coward in 1910. Further proof that 

 vitamine A is not necessarily associated 

 with carotinoids was furnished by Palmer 

 and Kennedy, who grew normal rats on 

 carotinoid-free diet. 



An association of carotinoids with other 

 vitamines than vitamine A has also 

 been suggested, but Palmer says that it 

 hardly seems possible that anyone with a 

 thorough knowledge of the distribution 

 and properties of vitamine B could give 

 this suggestion any serious thought. 



In Palmer's book on the carotinoids he 

 states that the yellow pigments may be 

 considered in three possible relations, 

 which have a bearing on the vitamine 

 situation. 



In the first place, Rosenheim and Drum- 

 mond have expressed the view that the 

 deflection of xanthophyll to the ovaries 

 during egg laying indicates that the 

 pigment is required for a definite and 

 important function in the egg and that 

 this fact supports the theory that the 

 carotinoids are related to the vitamines. 



However, Palmer says that it is just as 

 reasonable to suppose that the egg yolk is 

 an easier path of excretion for a fat soluble 

 pigment than the skin, just as the kidneys 

 are ordinarily the chief path of excretion 

 of water soluble waste products. 



Lastly, it is known from experiments 

 that Nile blue is transported to the pig- 

 ment granules in the epidermis of the 

 chicken skin in association with fatty 

 acids. When salmon migrate to the 

 spawning bed they eat nothing. When 

 the fish come from the sea their flesh is a 

 strong pink color while the small ovaries 

 are yellow brown. As the reproductive 



