BOXES OF THE LEG. 



139 



large projections. The larger (5) is called the great, and the 

 smaller (7) the lesser trochanter, which serve for the attach- 

 ment of the principal motory muscles of the thigh. The body 

 (9 9) is arched before, and slightly concave behind, where we 

 observe a rough projecting line (linea aspera) (10), which like- 

 wise affords a firm surface for the attachment of the muscles of 

 the thigh. The lower end of the body expands into two large 

 condyles (12, 13), of which the inner (13) is longer and larger. 

 Fig. 134 represents a front view, and fig. 133 a back view of the 

 femur. The coudyles move upon the head of the Fig. 137. 

 tibia only in one plane. The knee joint is, there- 

 fore, apure hinge, its motions being restricted by 

 lateral and crucial ligaments, whilst the round 

 head of the femur forms, with the acetabulum, 



a ball and socket joint, and executes thereby 



movements in all directions. 



[ 265. THE LEG- (fig. 137) consists of two 



bones, the tibia (n) and fibula (in). The 



tibia has a broad head, on which the condyles 



of the femur play ; to its upper surface is 



attached, by a ligament, a small round bone, 



the patella (i), or knee-pan, which protects 



the joint in front, and changes the direction 



of the tendons descending from the thigh to 



be inserted into the tibia, and thereby enabling 



them to act more advantageously upon the leg. 



The fibula (in) is a slender bone placed at the 



external side of the tibia. It affords attachment 



to muscles, and assists in the formation of the 



ankle joint. The latter joint, however, being 



formed chiefly by the lower end of the tibia; that 



bone supporting the entire weight of the body. 

 [ 266. THE FOOT consists of the TARSUS, 



METATARSUS, and TOES. Fig. 138 shews 



these parts of the foot. A is the tarsus, B the 



Fit?. 138. 



Tin 



III 



