66 ELEMENTS OF PHYSIOLOGY 



110. The Leg. The skeleton of a lower limb has a strik- 

 ing resemblance to that of an upper limb (Fig. 61). The 

 hip girdle, corresponding to the shoulder girdle, forms 

 the hip. The hip bones, or innominate ("nameless," 

 because they do not resemble anything) bones, are 

 large, flat, and somewhat semicircular in shape. They 

 meet in front (Fig. 62), but behind they join the portion 

 of the spinal column called the sacrum, which separates 



FIG. 62. The Pelvis. 



Sac, Sacrum , cocc, coccyx ; acet (acetabulum) , cup for head of femur ; 5LV, fifth lumbar 



vertebra. 



them and forms, as it were, the keystone of the arch (Fig. 

 62). Thus is formed a large band of bone inclosing a 

 basin-shaped space, called the pelvis (" basin "), which con- 

 tains the bladder and other organs. There is a deep socket 

 at the side in each innominate bone. This socket is occu- 

 pied by the round head found on the upper end of the 

 thigh bone, or femur. The femur is the largest and long- 

 est bone in the body (Figs. 63, 64). 



111. The leg below the knee, like the forearm, is com- 

 posed of two parallel bones. They are not equal in size, 



