152 Scientific Proceedings (120). 



free from calcium or nearly free from it and was invaded in an 

 irregular manner by the vascular elements of the shaft. In con- 

 sequence the cartilage extended toward the shaft in irregular 

 prolongations. The cells of the cartilage in proximity to the shaft 

 showed evidences of degeneration and metaplasia. The inter- 

 mediate zone was composed of cartilage in a more or less degen- 

 erated state, osteoid trabecular, blood vessels surrounded by 

 marrow elements, a few deposits of calcium for the most part 

 situated near the periphery and connective tissue. The trabecular 

 of the shaft were bordered by rather broad zones of osteoid. A 

 loosely arranged fibrous tissue invested many of the trabecular. 

 In those places in which it filled in the spaces between them, it 

 gave rise to histological pictures which closely resembled those 

 presented by the fibrous marrow in the rickets of human beings. 



The pathological condition induced in the bones by the diets 

 of the second group did not, however, exactly correspond at all 

 points to that usually found in the human subjects of the disease. 

 The cartilage was invaded and its columnar arrangement was 

 disrupted to a less extent than is commonly the case in the rickets 

 of human beings. The metaphysis was composed in larger part 

 by osteoid trabecular. Though these osteoid trabecular were free 

 from calcium deposition, they, nevertheless, retained a certain 

 semblance of orderly arrangement. The osteoid zones about the 

 trabecular were not so broad as in the rats on the diets of the first 

 group, though they were quite as broad as the osteoid borders in 

 the bones of rachitic children. Cells evidently derived from the 

 fixed tissues with large basophilic granulations were numerous in 

 the immediate vicinity of the trabecular. Resorptive activity was 

 exceedingly marked. In the fundamental respects, however, in 

 particular, degeneration and metaplastic changes in the cartilage, 

 defective calcification of the cartilage and trabecular and the con- 

 sequent osteoid production, the irregular invasion of the cartilage 

 and the production of a rachitic intermediary zone, the patho- 

 logical conditions produced by the faulty diets of the second group 

 corresponded to the rickets of human beings. While one of the 

 diets in question, diet 2638, did not give constant results, in some 

 animals it produced a pathological condition corresponding to 

 that found in human rickets even in its minor details. 



