170 THE MAMMALIA. 



contrary, it is found that the Anoplotherium from 

 the Eocene of the Paris limestone, which has left 

 no descendants, shows scarcely any traces of the 

 second and fifth toes ; and by the side of the 

 Hyopotamus, with four-toed feet, there existed the 

 distinctly two-toed Gelocus, 1 whose extremities are 

 almost as much reduced as the Deer ; and the same 

 is the case with Diplopus. It would be rash to 

 attempt to determine, among all these varied forms, 

 which was the actual and definite primary form for 

 the Deer or any other living group of the Rumi- 

 nants ; still, any attempt to explain the striking 

 relation between the past and present forms, other- 

 wise than by means of the theory of descent and 

 in accordance with Darwin's principle, cannot be 

 expected from us. The share which homoeogenetic 

 approximation may have taken in this connection 

 has already been discussed. 



The same result is obtained by the condition of 

 the teeth; and, as in the case of the limbs, the 

 teeth must not be examined in the Deer by them- 

 selves, the whole group of Ruminants must, first 

 of all, be compared with the fossil forms. 



Among our living Hoofed animals the Giraffe 



1 Filhol, 'Mammiteres fossiles de Eonzon, 1882,' Gelocus, 

 Ancodus, and others ; their Relation to Hyopotamus. 



