A CONTRIBUTION TO THE COMPARATIVE 

 HISTOLOGY OF THE FEMUR 



By J. S. FOOTE, M. D. 



I. INTRODUCTION 



The investigations in the Comparative Histology of the Femur were begun 

 by the writer in 1909, and were suggested by a section of the turkey's femur 

 which he had casually prepared and which seemed to show a type of bone 

 structure quite unlike tliat usually described. Before long, other ] )eeuliarities 

 were noticed and it was then decided to extend the study to various animals for 

 the purpose of determining what variations of bone structure may exist, and, if 

 possible, what is their significance. Accordingly, the femora of 46 different 

 animals, including amphibians, reptiles, birds, mammals, and man, were ex- 

 amined as they could be obtained and described, the report being published in 

 the Transactions of the American Miscroseopical Society of April, 1911.' The 

 number of femora examined up to that time was small, nevertheless the results 

 of the work were so new and interesting as to warrant further study. 



Following the report and upon the suggestion of Dr. Ales Hrdlicka, curator 

 of the Division of Physical Anthropology in tlie United States National Museum, 

 the writer extended his investigations to a much greater number of orders, 

 genera, and species of the lower animals, and finally also to the three main 

 races of man — black, yellow-brown, and white — the latter including the ancient 

 Egyptian. An abstract of the results of the advanced investigations was pub- 

 lished in 1913 by the Smitlisonian Institution.' The studies, however, were still 

 continued as long as material was available and finally have been combined in 

 this memoir which presents a comprehensive view of the whole work thus 

 far accomplished. In all, 600 sections have been examined; of these 440 are 

 described. 



The present report includes, besides the text, 467 drawings. Tliey were 

 made, for the most part, directly from the slides with the help of the Edinger 

 Drawing Apjjaratus, and are illustrations of the structural bone units, of the 

 types and combinations of bone types in their various stages of dil'ferentiation, 



' Foote, J. S. Tlie comparative histology of femora! bones. Trans, Amer. Micras. Soc, 30, 1911, 

 pp. 87-140, 9 plates. 



- Foote, J. S. The comparative histology of the femur. Smithsonian Miscellaneous Collections, 

 Vol. 61, No. 8 (Publication 2232), Washington, 1913, pp. 1-9, 3 plates. 



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