B 



CAROTENOIDS IN ANIMALS 



91 



(iv) Nerve tissues 



Nerves of humans and cows^^^: Caro- Peripheral nerves^^^: Carotenoids. 



tenoids. 



(v) Inner Organs, Glands, Secretions^^^ 



Corpora rubra of cows^^®: ^-Carotene. 



Corpus luteum of cows^"' ^^°' ^^^' ^*^' 

 353, 354, 355- a-Carotene, /5-carotene 

 and traces of xanthophyll. 



Gallstones (cattle)'"' '*': Carotene, 

 xanthophyll. 



Heart tissue s^^^: Carotenoids. 



Hypophyses of cattle^^^: Carotenoids. 



Kidneys (human beings, horses, 

 guinea pigs, cats, dogs, pigs)^'*' ^'^^' 

 338,337,338,326; Carotcnc, xanthophyll. 



Liver^^^' ^^^' ^^^: Carotenoids. 



Liver (human)'^'; Carotene, lycopene, 

 zeaxanthin, xanthophyll, violaxan- 

 thin(?), 2 pigments of unknown 

 constitution (degradation products 

 of /3-carotene) . 



Liver (human)'*': Carotene, xantho- 

 phyll, lycopene. 



Liver (pigs)'**: Carotene. 



Milk fats (all mammals)'", seo, 36i, 362, 

 363, 364. Carotene, a little xantho- 

 phyll, pseudo-a-carotene( ?)'^*. 



Placenta (cow)'®^' '^2; /9-Carotene. 



Placenta (human)'^^. 357, 355, 322, 358. 

 Carotene and xanthophyll. 



Skin^^^: Carotenoids'*^. 



Spleen^^^: Carotene. 



Testes (various mammals)'^': Caro- 

 tenoids. 



Yellow skin of diabetic subfects^^^' ^^^' 

 "": Carotenoids. 



Yellow skin produced by special diet 

 '*': Carotenoid'*®. 



(vi) Other parts 



Blood of umbilical cord^''^: Carotene. 

 Colostrum (women)"^: Carotene. 



Retina^''^: jS-Carotene, retinene. 



b) Birds 



The numerous investigations on the pigments of the plumage of birds bear 

 witness to the great interest shown by chemists and zoologists in these natural 

 compounds. Other parts of birds, such as the skin, the inner organs, and the 

 fat tissues, have also been repeatedly examined. The majority of these studies, 

 have been carried out, however, with very small amounts of material, and have 

 therefore yielded merely qualitative data. Crystalline pigments have only been 

 obtained very rarely. Most of the available information consists of spectroscopic 

 data or even colour reactions with concentrated sulphuric acid or antimony 

 trichloride and cannot, therefore, be regarded as conclusive. 



The following parts of birds have been examined: 



(i) Feathers ; 

 (ii) Fat tissues; 



(iii) Foot skin, body skin, beaks; 

 (iv) Blood serum and inner organs ; 

 (v) Egg yolk. 

 References p. gg-ioy. 



