THE CERVID^E, OR DEER. 169 



25, B). There both outer toes are still somewhat 

 longer and stronger. Trapezoid and os magnum 

 have not yet coalesced ; the metacarpals n and v 

 are still connected with the carpals. Upon the whole, 

 however, the differences between the living and the 

 Miocene representatives of the pair-hoofed group 

 are so slight that Hycemoschus may be called a 

 surviving form of primary ruminant. 



The hind limbs of the Hycemoschus are more 

 changed than the front limbs, owing to the two 

 principal metatarsals having almost completely 

 coalesced. A greater reduction of the hind limbs 

 is often met with : for instance, the peccary has 

 only one rudimentary toe on its back foot, whereas 

 there are two on the fore-foot. This difference in 

 the construction of the front and back limbs is, we 

 think, to be explained by the greater amount of 

 work which the hind legs have to accomplish ; for, 

 as was said above, we look upon a reduction of this 

 kind as an advance in the power of the adaptation. 

 But, while we are naturally led back from our 

 present Deer and Tragulidse to those early four- 

 toed Hyopotamidae, we do not in any way mean to 

 affirm that up to the Middle Tertiary all animals of 

 the Ruminant group without horns or antlers 

 possessed the full number of four toes. On the 



