THE TARSUS, OR ANKLE. 



141 



rounded. The surfaces are slightly rough, for the attach- 

 ment of muscles. The head is pyramidal in form, pre- 

 sents an inner articular surface for the side of the head 

 of the tibia; the external, ante- 

 rior, and posterior surfaces are 

 rough, for the attachment of 

 ligaments; from its upper part 

 projects the styloid process, to 

 which is attached the tendon of 

 the biceps muscle. The infe^ 

 rior extremity projects an inch 

 to an inch and a quarter below 

 the inferior surface of the tibia, 

 and forms the outer malleolus. 

 Posteriorly it presents the 

 groove for the tendons of the 

 peroneus longus and brevis. 

 Externally it is subcutaneous; 

 internally it presents the articu- 

 lar sin-fane for the tibia; below 

 is the articular surface for the 

 outer side of the astragalus. 

 The outer malleolus is some- 

 what pointed below, and serves 

 for the attachment of liga- 

 ments. 



The fibula develops by 

 three centres, one for the 

 shaft, one for the upper, and 

 the other for the lower 

 tremity. 



THE TARSUS, OR ANKLE. 



The tarsus, or ankle, is composed of seven bones, 

 astragalus, os calcis, scaphoid, cuboid, external, middle, 



ex- FIG. 67. THE TIBIA AND FIBULA, 

 POSTERIOR SURFACE. 



