SKELETON AND TEETH 



87 



camels and true ruminants, the bone has apparently disap- 

 peared. The young animal, however, shows that the ends 

 of the fibula have been retained and the shaft completely lost ; 

 the upper end is in the adult firmly fused with the tibia and, 



Fig. 37.— Bones of left 

 lower leg of Wolf , front 

 side. T., tibia. F., 

 fibula, sp. spine of 

 tibia, en. c n e m i a 1 

 crest, i.m., internal 

 malleolus, e.m., ex- 

 ternal malleolus. 



Fig. 38.— Bones of left 

 lower leg of Horse 

 (much more reduced), 

 en. cnemial crest. F., 

 lower end of fibula, 

 coossified with tibia. 

 Other letters as in 

 Fig. 37. 



Fig. 39. — Bones cf lower 

 leg, left side, of Tapir. 

 T., tibia. F., fibula, 

 s/;., spine of tibia, en., 

 cnemial crest, i.m., in- 

 ternal malleolus, e.ni., 

 external malleolus. 

 N.B. This figure is on 

 a much larger scale than 

 Fig. 38. 



in the horses, the lower end is also, but this remains separate 

 in the ruminants and camels, forming the malleolar hone, 

 which is wedged in between the tibia and the heel-bone. 

 Because of its importance in holding the ankle-bone in place, 

 this lower end of the fibula is never lost in any land mammal. 

 The hind foot, or pes, hke the manus, is clearly divisible 



