THE HIND-LIMB 301 



by the intercondylar notch, which is con- 

 tinuous with a deep groove on the front of 

 the bone, along which the patella slides. 



ii. The patella, or knee-pan, is a large sesamoid 

 bone in the tendon of the extensor muscles of 

 the leg. It is connected by Ugaments with 

 the tibia, and slides in the groove on the lower 

 end of the femur. 



At the back of the knee-joint are smaller 

 sesamoids, the fabellae. 



2. The leg contains two bones, which are very imequal in 



size, and in the adult are fused together distally. 



i. The tibia, or preaxial bone of the leg, is a stout 

 and straight bone, the longest in the body. 

 Its enlarged proximal end, which is triangular 

 in section, bears on its upper surface two oval 

 surfaces for articulation with the condyles of 

 the femur. Below the head is the prominent 

 cnemial crest, extending some distance down 

 the anterior surface of the bone. 



The distal end of the tibia, which is indis- 

 tingnishably fused with the lower end of the 

 fibula, bears an articular surface for the 

 astragalus. 



ii. The fibula, or postaxial bone, is very slender : 

 its proximal end is distinct, and articulates 

 with a facet on the outer surface of the head 

 of the tibia. 



Its distal portion is completely fused with 

 the tibia, and bears at its end an articular 

 surface for the calcaneum. 



3. The tarsus consists, in the rabbit, of six bones, arranged, 



like the bones of the wrist, in a proximal and a distal 

 row, with a central bone between them. The typical 

 tarsus exactly corresponds to the typical carpus in 

 number and arrangement of bones. 



