PELVIC LIMBS. 



79 



deficiency to the bottom of the cup. The deficiency, incisura 

 acetabuli, or acetabular notch {d'), is closed naturally by a 

 ligament, and the groove gives origin to the ligament (liga- 

 mentum teres) which attaches the head of the femur. 



Femur (Fig. 56). — The femur is the 

 proximal bone of the posterior extremity. 

 It consists of enlarged proximal and 

 distal ends connected by a nearly cylin- J^- 

 drical shaft. The proximal end presents 

 on its medial side a hemispherical head 

 [a) which fits into the acetabulum. It is 

 supported by a neck (/;) which is con- 

 tracted near the head and expanded dorso- 

 ventrally where it joins the remainder of 

 the bone. The medial surface of the head 

 presents near its ventral border a depres- 

 sion {c) for the insertion of the round liga- 

 ment of the femur. Ventrad the articular 

 surface of the head extends as an acute 

 projection onto the shaft, so that the whole 

 articular surface appears somewhat pear- 

 shaped. On the lateral side of the proxi- 

 mal end opposite the head is a projecting 

 mass, the great trochanter {d), forming 

 the end of the shaft. On the medial side 

 of the great trochanter at its junction with 

 the neck is a deep fossa, the trochanteric 

 fossa or digital fossa [c) for the insertion 

 of muscles. 



the great trochanter a ridge, the inter- a, head; b, neck; c, de- 

 trochanteric line (/), is continued distad, P'^^^f"" fc"- 'o""^! 'iga- 



^ ^\ , ment; n, great troclianter; 



ending in a pyramidal projection, the e, troclianteiic fossa; /, 

 lesser trochanter (^), wliich serves for iS^ru'Ser; 'rii„S 

 the insertion of muscles. A second ridge aspeia; ?, medial condyle; 



l.-rom the ventral surface of "^ vS^^rLoE:"™' 



J, lateral condyle; /', inter- 

 condyloid fossa; /, lateral 



is continued to the lesser trochanter from 



the neck. A slight but well-marked epicondyie. 



ridge, the Spiral ridge or line, runs round two sides of the 



neck parallel to the second ridge. 



