140 THE VITAMINS 



kilogram were carrots protective for dogs. Rutabagas appeared even 

 less effective. 



The fair agreement in the distribution and relative concentration 

 of the factors in various food materials preventive of the vitamin 

 G (B2) deficiency in rats, pellagra in man, and black-tongue in dogs 

 respectively, led both Aykroyd and Roscoe (1929) and Goldberger 

 and his collaborators ( 1928) to express their belief in the fundamental 

 identity of these three conditions. 



Relation to Nutrition 



Many of the observations upon the nutritional deficiency which de- 

 velops when vitamin G is lacking or insufficiently supplied have been 

 mentioned earlier in the chapter in the account of the differentiation 

 of vitamins B and G. It was there noted that as early as 1926 Gold- 

 berger and his colleagues pointed out the probable connection between 

 the pathological conditions observed in human pellagra, canine black- 

 tongue, and the dermatitis of rats resulting from a deficiency of the 

 more thermostable part of the vitamin B complex. Chittenden and 

 Underbill (1917) had experimentally induced by diet a pathological 

 condition in dogs, in many respects similar to pellagra. Underbill and 

 Mendel (1925, 1928) made a further study of this condition. 



When the animals first showed signs of loss of appetite, the mouth 

 revealed an inflamed condition of the gums as well as the inside of the 

 lips, and a characteristic red line extending around the teeth. When 

 autopsied. Dr. Robert A. Lambert reported characteristic acute pharyn- 

 gitis, also lesions of the esophagus, stomach and the upper portion of 

 the small intestines. These findings, though less severe in character than 

 those reported by Chittenden and Underbill in 1917, corroborated the 

 earlier symptoms which were reported as pellagra-like. 



Neither compressed yeast in amounts sufficient to supply vitamin B 

 requirements of the dog nor cod-liver oil protected against the inci- 

 dence of the disease nor prolonged life. Meat and pig's liver prolonged 

 Hfe. Butter (5 per cent of the ration) cured and maintained the animal 

 in good condition over long periods of time. Egg yolk, though contain- 

 ing the potent factor, seemed less effective than butter ; boiled unpeeled 

 carrots were more potent, and a lard extract of carrots also alleviated 

 the symptoms. The effective agent in butterfat was apparently quite 

 labile and associated with the yellow coloring matter, for the butter 

 lost its potency as well as some of its color during a period of from 9 

 to 11 months of cold storage. These two facts led to a further investi- 

 gation of the relationship between the effective agent and carotinoids 



