NO. 3 



COMPARATIVE HISTOLOGY OF FEMUR FOOTE 



167 



XIII. MAN— YELLOW-BROWN RACE 

 General Character of the Femur 



With one exception the femora of the yellow-brown race are pre-Colum- 

 bian. The series includes infantile, adolescent, and adult bones from the 

 Pueblo, Chicama, and Pachaeamac Indians. 



The general shape of these femora is nearer circular than it is in the 

 black or white races. The medullary canals were filled with marrow and 

 cancellous bone. The medullary surfaces are irregular and corrugated. The 

 medullary index varies from 19% to 100%, with an average of 43.8%. 



Nearly all of the femora are composed of type combinations. The propor- 

 tion of first type units is larger than it is in other races. 



Detailed Examination 



right femur of a pueblo indian child, one year old. no. 258675 (z), 



u. s. nat. mus. 



PL. 25, Fig. 341. Syn. Tab. IX 



Antero-posterior diameter of bone, 8 mm. ; lateral, 7.5 mm. 

 Antero-posterior diameter of medullary canal, 4.5 mm. ; lateral, 4 mm. 

 The medullary canal is full. Medullary index, 43%. 



Structure. — Around the external portion of the section is a horseshoe- 

 shaped band of crude Haversian systems in various stages of differentiation. 

 Some are round, some elongated, and many are irregular in shape. Their 

 Haversian canals of the (lb) differentiation are relatively large and surrounded 

 by lamella? with oval lacunas and rather infrequent canalieuli. The toe of the 

 shoe is best developed and widest. 



Underneath the Haversian band is a wider horseshoe band, forming the 

 remainder of the section, and composed of laminae, between which are concen- 

 tric canals. In the anterior and outer wall the lamina 1 are assuming the shape 

 of very much elongated Haversian systems. The posterior ridge is composed 

 of crude, elongated Haversian systems, which extend from the external to the 

 medullary surface and at right angles to the lamina? of the lateral wall. The 

 systems have wide Haversian canals, surrounded by lamella? with oval lacuna? 

 and bushy canalieuli. A large vascular canal is seen in the inner posterior 

 wall. 



The internal circumferential lamella? surround the medullary canal in the 

 form of cancellous bone. 

 Type II-III, lb. 



12 



