664 EXPERIMENT STATION RECORD. [Vol.43 



with the relation between fat-soluble A and the antirachitic factor, the relation 

 of the latter to age and to the energy-bearing portions of the diet, and the 

 effect of exercise, unhygienic surroundings, etc . on the development of rickets. 

 The discussion of these topics supplements earlier work of the author (E. S. 

 R., 41, p. 3G4), Attention is called to the difference in distribution of the fat- 

 soluble factor and the antirachitic accessory factor in vegetable fats, and to 

 the importance of the fat-soluble factor for the growth of rats and its probable 

 unimportance in t.^ie growth per se of puppies and children. The suggestion is 

 made that both of these dilTeronc(>s can pfobably be explained by variations in 

 the general and intermediate melal)olisra of these animals, but that care should 

 be taken not to confuse the two types of work, namely, the growth experiments 

 on»rats and the rickets experiments on puppies. 



Other points brought out in the discussion are that the younger the animal 

 the more necessary is the antirachitic accessory factor in the diet until some 

 essential process or secretion has developed which efCectu«tlly prevents the de- 

 velopment of rickets whatever the diet; that an increase in the protein of the 

 diet aids the antirachitic vitamin so that less of it will suffice to keep the growth 

 normal, while an increase in carbohydrate, especially when it results in the 

 storage of fat, appears to render additional antirachitic vitamin imperative; 

 and that exercise is not the prime factor in the etiology of rickets but is a 

 secondary factor in the prevention of the disease in being a stimulant to the 

 general metabolism. 



Vitamin studies. — V, The antiscorbutic properties of raw beef, R. A. 

 DuTCHER, E. M. PiEKSON, and A. Biester {Jour. Biol. Chem., 1/2 {1920), No. 2, 

 pp. 301-310). — This paper, in continuation of the vitamin studies previously 

 noted (E. S. R., 41, p. 766), consists of the detailed report of a study of the 

 antiscorbutic properties of raw lean beef. The conclusion that this material 

 is lacking in antiscorbutic properties has been noted in a preliminary report 

 from another soui-ce (E. S. R., 41, p. S61). 



The pathogenesis of deficiency disease, R. McCarkison {Indian Jour. Med. 

 Research, 7 {1919), No. 2, pp. 269-3 Jf5, pis. 29, figs. 2).— In continuation of the 

 investigation previously noted (E. S. R., 42, p. 463), five papers are presented, 

 V. Histopathology (pp. 269-278). — This paper deals with the histological 

 changes observed in the spleen, liver, pancreas, kidneys, pituitary body, and 

 thyroids of pigeons fed exclusively on a diet of autoclaved milled rice, the study 

 being a continuation of the one previously reported in which histological changes 

 in the intestines and testicles of pigeons so fed were noted. 



In general the histopathological changes found in the various organs were 

 of two kinds, necrobiosis and congestion. In the thymus, spleen, and testicles 

 the disappearance of tissue cells was the more prominent change. In the 

 intestines, liver, pancreas, and kidneys congestion, with hemorrhagic infiltra- 

 tion, was often the more prominent feature. In the thyroids and the glandular 

 part of the pituitary both features were present, but usually in mild degree. 



Arranged in the order of severity in which these changes occurred, it is 

 shown that " the organs which suffer most are those which are least essential 

 to the life of the individual. Next in order are the organs of digestion and 

 assimilation, then the organs of excretion, and, lastly, the organs of internal 

 secretion. That the central nervous system suffers least, from the point of 

 view of organic lesions, is shown by the rapidity with which the nervous 

 symptoms due to the deficient diet can be controlled or abated by the ad- 

 ministration of vitaminic substances. It seems probable that the cellular 

 elements of the organs least essential to the life of the individual are utilized to 



