134 CAROTINOIDS AND RELATED PIGMENTS 



report carotin in all cases, the amount varying from relatively large 

 amounts in the case of the horse and guinea pig to very little in the 

 case of swine, cats and dogs. Findlay reported a small amount of 

 carotin-like pigment in the suprarenals of the sheep. Palmer and 

 Kennedy (1921) were unable to find any pigment soluble in alcohol 

 or petroleum ether in the suprarenals of albino rats. 



There has been very little study of the pigments of mammalian 

 liver from the standpoint of carotinoids. It is difficult tissue to 

 examine because it is rich in pigments of unknown character which 

 are soluble in certain of the fat solvents, and also because one of 

 these pigments, at least, gives a color reaction with con. H.,S0 4 

 which may easily be mistaken for a carotinoid reaction. It is to be 

 expected that the liver of animals whose blood and adipose tissue 

 may be rich in carotinoids will also contain these pigments, e.g., that 

 the human liver will contain varying amounts of both carotin and 

 xanthophylls, and that the liver of the cow and horse will contain 

 carotin. Van den Bergh, Mullcr and Broekmeycr (1920) have found 

 this to be the case. On the other hand the statement of these investi- 

 gators that the liver of swine, cats, dogs and guinea pigs contains 

 small amounts of carotinoids is to be accepted with reserve until the 

 experimental evidence for this statement is extended to include the 

 spectroscopic and adsorption properties of the pigments isolated. 

 These investigators based their conclusions on color reactions with 

 concentrated acids and upon solubility in carotinoid solvents and upon 

 the phase test. None of these properties is properly to be regarded 

 as specific for carotinoids. 



Nerves. Meschcde (1865, 1872) first observed yellow pigment in 

 nerve cells which could be extracted with fat solvents. Rosin (1896) 

 first associated the pigment with the lipochromes then rising into 

 prominence. He noted its presence in the human and in cattle, and 

 its absence from the nerve cells of the dog, cat, rabbit, rat and mouse. 

 Rosin and Fenyvessey (1900) noted that the pigment was absent from 

 the nerve cells of the new born, but that it was always present in 

 the nerve cell tissue of adult humans. Following the studies of Lu- 

 barsch (1902), who regarded the lipochrome as an "abnutzung" 

 (wear-and-tear) product of endogenous origin, pathologists have at- 

 tached significance to the increase in lipochrome pigmentation in nerve 

 cells which have been observed in disease. Dolley and Guthrie (1919), 

 however, have made a careful study of the occurrence of chromolipoid 

 in the nerve cell of man and animals and have found that it can be 



