THE FEMUR. 



357 



Frontal sections through the back part of the condyles show that the inner is nearly 

 symmetrical in its convexity from side to side, while the inferior surface of the outer 



Fig. 372. 



Outer head of gastrocnemius 



External lateral ligament 



External tibial facet 



Popliteal groove 



Patellar facet 



Lower end of right femur, outer aspect. 



slants upward and inward. The length of the articular surface of the inner condyle 

 from the back to the line marking of^ the patellar facet is considerably greater 

 (perhaps two centimetres) than that of the outer. 



Fig. 373. 



Patellar surface 



External tuberositj 



Limit of patellar surface 



Internal tuberosity 



Lower end of right femur from below. 



Structure. — Transverse sections in series through the whole length of the 

 femur are very instructive. They show the great strength of the shaft, the thick- 

 ness of its walls, the smallness of the central canal, and the addition made by the 

 linea aspera ; likewise that the shaft becomes four-sided both above and below, 

 and that in the latter region the greater diameter is transverse. Coincident with 

 these changes are a great diminution of the thickness of the walls and a great increase 

 of the spongy tissue. The weakness of the walls just above the knee is very striking. 

 The architecture of the condyles is well exhibited, consisting of vertical plates run- 



