504 THE RABBIT CHAP. 



Close to the proximal end of the femur, on its inner 

 (preaxial) border, is a rounded, projecting head for articulation 

 with the acetabulum : the actual end of the bone is formed 

 by a strong process, the great trochanter, while just distal to 

 the head is a lesser trochanter, and opposite this, on the 

 outer (postaxial) side, a third trochanter. The distal end of 

 the bone bears two large condyles, separated from one 

 another by a notch, for articulation with the tibia : this 

 notch is continuous with a groove extending for a short 

 distance along the anterior (dorsal) surface of the femur in 

 which a large sesamoid bone (p. 502), the knee-cap or 

 patella, slides : the patella lies in the tendon of the extensor 

 muscles of the leg, and is connected by ligament with the 

 tibia. Two other sesamoid bones, the fabellce, occur on the 

 opposite side of the knee-joint. 



The tibia, or inner (preaxial) bone of the shank, is much 

 larger than the fibula, the distal half of which in the adult 

 becomes completely fused with it. The proximal end of the 

 tibia bears two slightly concave articular surfaces for the 

 condyles of the femur, and distally it articulates with the 

 tarsus : a prominent ridge the cnemial rm-/ extends along 

 the proximal end of its anterior (dorsal) surface. The 

 slender fibula is attached proximally to the tibia. 



The tarsus consists of six bones arranged in three rows. 

 In the proximal row (compare p. 51) are two tarsals, of which 

 the inner (preaxial) or astragalus probably corresponding 

 to two bones fused together, the tibiale and intermedium 

 has a large pulley-like surface for articulation with the tibia ; 

 while the outer (postaxial) calcaneum or fibulare articulates 

 with the fused end of the fibula, and is produced into a 

 strong heel or calcaneal process. In the middle row is a 

 single bone, the centrale (navicular) of the tarsus, and the 

 distal row is made up of three bones, the true first, together 



