172 



Anatomy of the Rabbit. 



M 



The fibular portion presents a transverse groove for the convex 

 articular surface of the calcaneus. Immediately above it, on the 

 lateral side of the bone, is a prominent projection, the lateral 

 malleolus (malleolus lateralis). It forms the anterior boundary 



of a groove which in the natural con- 

 dition lodges the insertion tendons of 

 / r-Sa ' the peroneal muscles. 



THE TARSUS. 



The tarsus (Fig. 72) comprises six 

 elements, the tarsal, or ankle-bones 



(ossa tarsi), which, like the correspond- 

 ing bones of the carpus, are arranged in 

 proximal and distal rows. An exception 

 is to be made, however, for one element, 

 the navicular, which occupies an inter- 

 mediate position. The proximal row 

 contains two elements, the talus and 

 calcaneus. The talus is medial and 

 also slightly dorsal in position. Its 

 proximal end, described as the body 

 (corpus tali), bears an extensive pulley- 

 like surface, the trochlea tali, for 

 articulation with the tibia, these two 

 surfaces together forming the chief 

 portion of the ankle-joint. Its distal 

 end, termed the head of the talus (caput 

 tali), provides a convex articular surface 

 for the navicular bone;, and is separated 

 from the larger trochlear portion by a 

 slightly constricted intermediate portion 

 or neck (collum tali). Its ventro- 

 lateral border is extensively articulated 

 with the calcaneus.- The latter is a 

 cylindrical element, fully twice as long 

 as the talus, since it is extended backward behind the ankle-joint, 

 as the tuber calcanei, or bone of the heel. Its dorsal surface 



P 



Fig. 72, The bones of the left 

 foot, viewed from the dorsal sur- 

 face: T, tarsus; M, metatarsus; P, 

 phalanges, II-V, the four meta- 

 tarsal bones: cb., cuboid; cl., 

 calcaneus; c.s., second cuneiform; 

 c.t., third cuneiform: f. a. .articular 

 surface for fibular side of the tibo- 

 iibula; n, navicular; t, talus; 

 t.c, tuber calcanei; t.t,, trochlea 

 tali. 



