THE CERVID^E, OR DEER. 163 



deer the first of these is smaller than the other 

 two, whereas in the roe the first one is of the pro- 

 portionate size. Now this arises from the fact that 

 the rudimentary digits of the deer have become 

 entirely detached from the metacarpals, and that 

 only the rudimentary upper end of it remains 

 (A, m). The roe still possesses the lower portion 

 of this bone (B, m) and, moreover, in connection 

 with the first phalange. The red deer is a ' plesio- 

 metacarpal ' cervide, the common roe a ' tele-meta- 

 carpal ' cervide. All the thirty-nine known species 

 of Cervidae, confined to the Old World, are con- 

 stituted like the deer with the exception of the two 

 species cf roe and the hornless Hydropotes in 

 China, with which we have only recently become 

 more intimately acquainted. These three latter 

 species, however, as regards the construction of 

 foot, are allied to the American deer. Of the 

 twenty American species with tele-metacarpals, one, 

 however, the Wapiti (Cervus canadensis), is not 

 related to the others, but to the Europe-Asiatic 

 group. 



From the formation of the foot, therefore, we 

 find an almost perfect means for distinguishing the 

 specise. And this leads to the very natural supposi- 

 tion that the American deer developed in the New 



