BONES AND MUSCLES OF LOWER EXTREMITY. 485 



lower extremities, this framework is much more firmly at- 

 tached to that of the trunk, than is the case with that which 

 supports the arms. It consists, on each side, of a bone which 

 in the adult state is single, though at an early age it is com- 

 posed of three distinct pieces ; and this is closely connected 

 with the sacrum behind, while it meets with its fellow in 

 front in such a manner as to form a sort of bason termed the 

 Pelvis. The spreading sides of this, formed by the iliac bones 

 (Fig. 213), afford support above to the viscera contained in 

 the abdomen ; and they give attachment by both surfaces to 

 large muscles by which the thigh-bone is moved, and by their 

 edges to large expanded muscles that pass upwards to the ribs 

 and sternum, and form the walls of the abdomen. Below this 

 spreading portion, we find the articular cavity of the thigh- 

 bone, which is so deep as almost to form a hemispheric cup 

 when it is completed by its cartilaginous border. The move- 

 ments of the thigh-bone are consequently more limited than 

 those of the arm ; but it is much less liable to displacement. 



646. The thigh, like the arm, contains but a single bone, 

 which is named the Femur. Its upper extremity is bent at 

 an angle ; and its rounded head is separated from the rest by 

 a narrow portion which is termed its neck. At the point 

 where this neck joins the shaft of the bone, there are two 

 large projections termed trochanters, one on the outer side and 

 the other on the inner ; these serve to give attachment to the 

 muscles by which the thigh is moved. Of these muscles, one 

 descends from the lumbar vertebrae, and passes-down with 

 another that rises from the upper expanded surface of the 

 pelvis, over the front border of the pelvis, to be attached 

 to the smaller and interior of the projections just mentioned ; 

 these with the assistance of other muscles raise or draw 

 forwards the thigh, an action which does not require in Man 

 to be performed with any great force. The muscles which 

 draw back the thigh, on the other hand, arise from the under 

 surface and back of the pelvis, where they form a very thick 

 fleshy mass ( u , 25 , fig. 226) ; and they pass to the larger and 

 external projection, and to a ridge which runs from it down 

 the thigh-bone. Other muscles which arise from the lower 

 border of the pelvis, serve to rotate the thigh upon its axis. 

 The lower end of the thigh-bone spreads into two large condyles, 

 on which the principal bone of the leg moves backwards and 



