490 



VITAMIN Bi2 



^'micromelia." A large number of the chicks which hatched showed kidney 

 damage with deposition of urates in the ureters. Normal development of 

 embryos and chicks was noted when the diet contained fish meal. The leg 

 deformity termed perosis was seen in many of the newly hatched progeny 

 of hens which had been on all-vegetable diets containing soybean meal 

 for more than 16 weeks. A supplement of herring fish meal markedly re- 

 duced the incidence of the deformity.^ Purified diets consisting principally 

 of sucrose and soybean protein were used for hens by Olcese and coworkers^ 

 in a study of the effects of vitamin B12 concentrates on embryonic develop- 

 ment. A high incidence of myoatrophy of the leg was seen in the deficient 



A 



i 



X 



Fig. 8. Embi\yos with myoatrophy (left and right) and normal embryo (center). 

 Removed from eggs on eighteenth day of incubation. (From Olcese et al.^) 



embryos (Fig. 8), characterized by very slender legs and by hemorrhages 

 in the muscles and the cartilage. Another sign of the deficiency included 

 high mortality during the sixteenth to eighteenth days of incubation with 

 the embryos dying in the malposition "head between thighs." The ab- 

 normalities were prevented by adding concentrates which supplied between 

 10 and 20 7 of vitamin B12 per kilogram of diet. 



B. RATS 



THOMAS H. JUKES and WILLIAM L. WILLIAMS 



Investigations were made into the causes of the high mortality in vita- 

 min Bi2-deficient rats in the period immediately following weaning.^ No 



^ J. S. Carver, J. McGinnis, and R. J. Evans, Poultry Sci. 26, 91 (1947). 

 ^ O. Olcese, J. R. Couch, J. H. Quisenberry, and P. B. Pearson, J. Nutrition 41, 

 423 (1950). 



