216 



SMITHSONIAN CONTRIBUTIONS TO KNOWLEDGE 



VOL. 35 



FIFTEENTH SECTION 



Antero-posterior diameter of bone, 31 mm. ; lateral, 52 mm. 



Structure. — The section is surrounded by lamellae with a few Haversian 

 systems. The remainder is cancellous. 



The type of bone of this femur was I-III, C, senile. The characteristic 

 units of structure were lamellae. 



2. Left Femur of a White Female, 38 Cm. Long. No. 301, Cr. Med. Coll. 



Transverse sections were made at intervals of 2.5 cm. and in the same 

 situations as they were in femur No. 300. 



HEAD 



Antero-posterior diameter of the equatorial section, 41 mm. ; lateral, 41 mm. 



Structure. — The section was surrounded by a thin envelope of bone, 0.5 mm. 

 in thickness, and composed of lamellae with a few very crude Haversian systems. 

 The remainder of the section was made up of cancellous bone much more dense 

 in the central portion than elsewhere and composed of lamellae. The walls of 

 the meshes radiated from the central portion toward the periphery. 



NECK 



Antero-posterior diameter, 30 mm. ; lateral, 27 mm. 



Structure. — The section was surrounded by an envelope of bone, varying 

 in thickness from 3 mm. in the posterior to 1 mm. in the lateral wall. The 

 enclosing envelope was composed of Haversian systems and some inter-Ha- 

 versian lamellae. The remainder of the section was made up of cancellous 

 bone, denser near the posterior wall, and radiating from this location toward 

 the periphery. It was considerably heavier than that of the head, and the walls 

 of the meshes were composed of lamellae with a few Haversian systems. 



SECTION THROUGH THE LESSER TROCHANTER 



Antero-posterior diameter, 34 mm.; lateral, 33 mm. 



Structure. — The section was surrounded by an envelope of bone, varying 

 in thickness from 4 mm. in the posterior to 1 mm. in the lateral wall. It was 

 composed chiefly of Haversian systems, between which were some inter-Hav- 

 versian lamellae. The calcar femorale was well marked and composed of lamellae 

 with many Haversian systems. The remainder of the section was made up of a 

 heavy cancellous bone composed of lamellae. 



