XIII. REQUIREMENTS 519 



quarters, unsteadiness, and a tendency to roll over on the side or hack. 

 Detailed pathological studies of the pigs described by Johnson and Xeuman 

 were reported by Thiersch^^ in collaboration with these authors. The defi- 

 cient animals showed a number of departures from normal. These included 

 increased size of the tongue and the liver, with vascularization and leuco- 

 cytic infiltration in the papillary bodies of the squamous cell layers of the 

 tongue. There were no apparent differences between groups with regard to 

 the red blood cell series, but the deficient pigs showed an increase in the 

 percentage of neutrophiles with a concomitant decrease in lymphocytes. 



TABLE XXIV 



Mean Bone Marrows before (A) and 5 Weeks after (B) 



Vitamin B12 Injection in Pigs** 



""J'he bone marrow findings are illustrated in Table XXIV. Megaloblasts 

 were not found, in contrast to their presence in the bone marrow of folic 

 acid-deficient pigs in a report by Heinle and coworkers.*^ New lesions were 

 not found in the spinal cord and sciatic nerves of pigs on the deficient diet 

 in spite of their gross symptoms of posterior incoordination and unsteadi- 

 ness of gait. Similar pathological findings were recorded with another series 

 of pigs on various levels of added vitamin B12 ranging from 17 to 68 7 per 

 kilogram of dry matter in the diet." 



" A. L. Neumann, B. C. Johnson, and J. B. Thiersch, J. Nuiriiion 40, 403 (1950). 

 *« R. W. Heinle, A. D. Welch, and J. A. Pritchard, J. Lab. Clin. Med. 33, 1647 (1948). 

 " A. L. Neumann, J. B. Thiersch, J. L. Krider, M. F. James, and B. C. Johnson, 



J. Animal Sci. 9, 83 (1950). 



