PELVIC LIMBS. 



79 



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

 acetabuli, or acetabular notch (</'), 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- 

 drical shaft. The proximal end presents 

 on its medial side a hemispherical head 

 (rt) 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 (<:) 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 (</), 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 (e) for the insertion 

 of muscles. From the ventral surface of 

 the great trochanter a ridge, the inter- 

 trochanteric line (/), is continued distad, 



a, head; b, neck; c, de- 



ending in a pyramidal projection, the <?, trochanteric fossa; /, 

 , / \ 1 i r intertrochanteric line- p, 



lesser trochanter (g)\ which serves for lesser trochanter; //? i in ; 



the insertion of muscles. A second ridge aspera; i, medial condyle; 



, - /, lateral condyle; /, inter- 



is continued to the lesser trochanter from condyloid fossa; /. lateral 

 the neck. A slight but well-marked epicondyle. 

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

 neck parallel to the second ridge. 



