352 



SCIENCE 



[N. S. Vol. L. No. 1293 



SPECIAL ARTICLES 



WHITE CORN VS. YELLOW CORN AND A PROB- 

 ABLE RELATION BETWEEN THE FAT- 

 SOLUBLE VITAMINE AND YELLOW 

 PLANT PIGMENTS 



As the importance of the vitamines in the 

 physiological economy of the animal is coming 

 to be appreciated, observations on their occur- 

 rence and their distribution in nature are 

 being rapidly accumulated in various labora- 

 tories. As is to be expected, with data on 

 vitamine distribution available, there is a 

 growing inclination to deduce therefrom, not 

 only evidence as to their possible role in living 

 organisms, but also a suitable working hy- 

 pothesis enabling one to predict in an un- 

 known whether the amount of vitamine is 

 liable to be large or small. Furthermore, from 

 the viewpoint of the chemist, it scarcely needs 

 to be emphasized what a step in advance it 

 would be if from their occurrence in nature 

 an idea could be obtained as to their possible 

 chemical character. 



We are still far distant from this goal in 

 the case of the anti-scorbutic and anti- 

 neuritic vitamines, but in the case of the fat- 

 soluble vitamine, the mere fact — as its name 

 indicates — that it is soluble in fats and also 

 its solubility in many fat solvents excludes 

 from consideration many compounds. 



Two years ago the writer experienced some 

 difficulty in getting rats to rear their young 

 on a ration which, to a considerable extent, 

 consisted of corn. Failure was often indi- 

 cated by an inflammation of the eyes — a xe- 

 rophthalmia, which Osborne and Mendel^ iirst 

 indicated as evidence of a deficiency of the 

 fat-soluble vitamine. ISTo further attention 

 Vvas paid to this difficulty beyond modifying 

 the ration to increase its content of this 

 dietary essential. Later, however, rats were 

 again put on a similar ration and no difficulty 

 Vvas experienced. With many other apparent 

 inconsistencies arising in a colony of a thou- 

 sand animals, and all of them bearing investi- 

 gation no immediate attention was given to 

 this matter. 



1 T. B. Osborne and L. B. Mendel, Jour. Biol. 

 Chem., 16, 431, 1913. 



During the course of the past year a con- 

 siderable amount of work dealing with the 

 occurrence of the fat-soluble vitamine in roots 

 was completed. It was indicated that, while 

 the colored roots such as carrots and sweet 

 potatoes are rich in this dietary essential,' 

 sugar beets, mangels, dasheens and Irish pota- 

 toes contain little or none of it. It was then 

 recalled that at the time that the difficulty 

 with female rats to rear their young had been 

 observed, it had been impossible to obtain 

 sound yellow corn on the local market and 

 white corn had been used instead. This had 

 been done in a part of the stock colony and as 

 the conditions for its maintenance are fairly 

 well standardized and not always under close 

 personal supervision the relation between the 

 slight modification in the ration and the dis- 

 astrous results had not been detected. 



It has now been conclusively demonstrated 

 with eight different varieties of corn which 

 are extensively grown in the middle west, that 

 while white corn contains no demonstrable 

 amounts of the fat-soluble vitamine, yellow 

 corn may contain sufficient amounts to allow 

 normal growth and reproduction in the rat. 

 One rat has successfully reared her young 

 after having been fed yellow corn suitably 

 supplemented with vitamine-free protein and 

 salts for seven months. On white corn, sim- 

 ilarly supplemented, young rats usually die in 

 three months with the typical symptoms of a 

 fat-soluble vitamine deficiency. 



These relations suggested the possibility of 

 correlating other instances of the simultaneous 

 occuiTcnce of the fat-soluble vitamine and 

 yellow plant pigments. We have at hand the 

 interesting observation of Osborne and MendeP 

 that while the oleo oils contain the vitamine, 

 the solid beef fats do not. . They state specific- 

 ally that the oleo oils were yellow while the 

 solid fats were colorless. Furthermore, they 

 were also able to separate the butter fats by 

 fractional crystallization into an active frac- 

 tion of the liquid fats — which was yellow — 

 and an inactive fraction — which was colorless. 



2 T. B. Osborne and L. B. Mendel, Jour. Biol. 

 Chem., 20, 379, 1915. 



