VITAMINS 135 



the algae and other plants which form an important part of 

 the diet of fish.* Amongst animal fats which are poor in vita- 

 min may be mentioned lard, whilst suet contains a fair propor- 

 tion. In view of the fact that the plant is the sole source of 

 vitamin, it is surprising to find that most vegetable oils ob- 

 tained from plant seeds have a low content of vitamin A, in 

 fact the storage organs of plants, and especially seeds, contain 

 little of this substance, f On the other hand, it has been shown 

 by Drummond and Coward J that large amounts of this sub- 

 stance are formed in green leaves, where it appears to be as- 

 sociated with the unsaponifiable portion of the fats rather than 

 with the protein, and that leaves deficient in chlorophyll ap- 

 parently are unable to effect its synthesis. Amongst the 

 marine algae, the green synthesize most, the red being much 

 less active. Fungi produce no vitamin A. 



The suggestion has been made that a probable relation 

 exists between vitamin A and carotinoids such as carotin and 

 xanthophyll, a view which has been disputed and, in fact, a 

 quantitive association between vitamin A and the yellow pig- 

 ments in the plant tissue is denied.ll Further, there appears 

 to be no definite relationship between vitamin A and lipo- 

 chromes in oils and fats.H 



With regard to vitamin B, the anti-neuritic or anti-beri- 

 beri vitamin, it has been shown that this substance is associ- 

 ated with the pericarp of rice and other grains and the germ 

 of wheat and rye. The proof of this is furnished by the fact 

 that the disease of beri-beri is associated with a diet consisting 

 almost exclusively of polished rice or white wheaten flour in 

 the preparation of which the pericarp and germ are respectively 

 removed, whereas rye flour and whole meal, in which the germ 

 is not entirely removed by milling, retain the active principle. 

 Whole potatoes, barley and beans also contain the anti-beri- 

 beri vitamin and the inclusion of these substances or of milk 

 in the diet ensures immunity from this disease. 



* Hjort : " Proc. Roy. Soc.," Lond., B., 1922, 93, 440. 



f Drummond and Zilva, "Journ. Soc. Chem. Ind.," 1922, 41, I25T. 



+ Drummond and Coward: " Biochem. Journ.," 1921, 15, 530. 



Steenbock : " Scie.ice," 1919, 50, 352 ; "Journ. Biol. Chem.," 1921, 46, 32 ; 



47. 303 ; 1922, 51, 63. 



|| Palmer: "Science," 1919, 50, i; Palmer and Kennedy: "Journ. Biol. 

 Chem.," 1921, 46, 559. 



U" Drummond and Coward: " Biochem. Journ." 1920, 14, 668. 



