272 CAROTINOIDS AND RELATED PIGMENTS 



An association of carotinoids with other vitamins than vitamin A 

 and with the results of other dietetic deficiencies has also been sug- 

 gested. Wiehuizen and others (1919) called attention to the low lipo- 

 chrome content of the blood serum in the case of human beriberi and 

 inferred a relationship between lipochromes and the antineuritic vita- 

 min by stating that animal and vegetable substances with a high 

 lipochrome content also have a high anti-beriberi value. It hardly 

 seems possible that anyone with a thorough knowledge of the distribu- 

 tion and properties of vitamin B could give this suggestion any serious 

 thought. 



A somewhat different conception of the significance of carotinoids 

 in nutrition is presented by McCarrison (1920) who noted that butter 

 made from milk of cows on green feed, and therefore high in .pigment, 

 afforded greater protection against edema of the adrenals of pigeons 

 fed on autoclaved rice than less highly colored butter fat made from 

 milk of cows on dry feed. McCarrison suggests that the hypothetical 

 anti-edema substance may be of the nature of a lipochrome, but his re- 

 sults can also be explained on the basis of the seasonal (dietary) varia- 

 tion in the vitamin A content of butter. 



We see from the foregoing di=rii?sion that there is little evidence to 

 support the idea that the carotinoids exert a definite physiological 

 function either in the species of animals in which they are visible after 

 absorption or in those animals which do not appear to absorb the pig- 

 ments at all. Curiously enough, however, a very practical use has been 

 made of the appearance of carotinoid pigments in certain of the visible 

 skin parts of some species which absorb the pigments. One may per- 

 haps be justified in discussing these uses briefly in connection with the 

 possible function of the pigments, although the function in these cases 

 is in the service of man. 



Practical poultry men in this country have recognized for a number 

 of years that a relation exists between the amount of yellow pigment 

 in the shanks, ear lobes, beaks, etc., of hens of certain breeds of poultry, 

 such as Leghorns, Plymouth Rocks, Wyandottes, and Rhode Island 

 Reds, and their previous egg laying activity. When Blakeslee and 

 Warner (1915a,b) and Blakeslee, Harris, Warner and Kirkpatrick 

 (1917) made extensive biometric analyses of data collected to deter- 

 mine the character and extent of this relation it was found that a defi- 

 nite positive correlation existed between pale shanks, ear lobes, beak, 

 etc., and a recent more or less large egg production. As the result of 

 these studies American poultry experts have made extensive use of the 



