166 THE MAMMALIA, 



survey both sides. But all of these observations, 

 which we owe principally to Sir Victor Brooke, 1 

 confirm Biitimeyer's remark that the form and 

 development of the antlers can only very cautiously 

 be made use of as a means for a strict classification 

 of the Cervidse. 



Even though animals with antlers are met with 

 as early as the Miocene, still the more complete 

 development of true Deer belongs to very recent 

 periods, and this explains their geographical dis- 

 tribution in the main. In addition to the circum- 

 polar reindeer and elk, Biitimeyer, agreeing with 

 Brooke, reckons twenty species to America and 

 thirty-nine to the Old World, many of which are 

 certainly doubtful. An exchange between East 

 and West seems evident, and yet, as we have seen, 

 it was extremely limited. The remarkable want of 

 deer in Africa beyond the desert, would have to be 

 explained, with Wallace, by the fact that there must 

 have existed obstacles almost insurmountable to 

 the animals when they first began to distribute ; 

 on the other hand, antelopes and even giraffes 

 had either already passed the open road south- 

 wards, or, owing to their organisation, had gra- 



1 Brooke, ' On the Classification of the Cervidse,' Proc. Zool. 

 Sac. 1S7& 



