688 MAMMALIAN ANATOMY 



trochanter on the inner edge of the posterior surface, where the upper 

 extremity joins the shaft. It is a small, pointed tuberosity connected 

 with the greater trochanter externally and above by the posterior 

 intertrochanteric line ; its upper and inner surfaces pass into the pos- 

 terior and inner surfaces of the neck of the femur, and its lower 

 surface is continued on the posterior surface of the shaft. On its apex 

 is inserted the tendon of the combined psoas and iliacus muscles. 



The anterior intertrochanteric line begins as a faint ridge on the 

 anterior surface of the upper extremity, a little below the superior 

 edge of the neck, and runs obliquely downward and inward to join 

 the internal limit of the linea aspera below the lesser trochanter on 

 the posterior internal aspect of the bone. It marks the upper border 

 of the area of origin of the vastus externus muscle and part of the 

 attachment of the capsular ligament. 



The Shaft is nearly straight, or very slightly curved from before 

 backward. It is of almost uniform diameter, slightly narrower above 

 the middle and expanding above and below as it passes into the 

 extremities. On cross-section, just below the lesser trochanter it is 

 triangular ; the base of the triangle represents the anterior surface, 

 and the apex is behind and on the inside at the inner branch of the 

 rough line on the posterior surface ; a transverse section taken at the 

 junction of the upper or lower third with the middle third is oval, 

 the transverse diameter being about one-sixth greater than the antero- 

 posterior diameter. The shaft presents an anterior and a posterior 

 surface, separated by an external and an internal border. 



The external border separates the outer parts of the anterior and 

 the posterior surface. It begins at the lower end of the outer edge of 

 the greater trochanter, is directed almost straight downward, and ends 

 in the external supracondyloid ridge of the lower extremity. 



The external border (Fig. 530) lies much nearer the posterior part 

 of the bone than the internal, and affords attachment by its entire 

 length to a broad sheet of the deep fascia of the thigh, known as the 

 fascia lata, with which are blended tendinous slips from the gluteus. 

 maximus and the aponeurosis of the tensor vaginse femoris muscle. 

 The fascia lata separates the areas of origin of the vastus externus 

 and crureus muscles from the area of insertion of the adductor femoris 

 muscle. 



The internal border (Fig. 531) is not distinctly marked in its 



