BLACK-TAILED DEER. 99 



as impassable as a Chinese wall to an entire species of animals 

 who have full physical power to traverse it, but do not, while 

 all others pass it unhesitatingly, is certainly a curious and an 

 interesting fact, well calculated to stimulate the naturalist to 

 seek for the cause, which has hitherto eluded all inquiries. 



In its own home, this animal seems to be healthy, vigorous, 

 and prolific, the females generally producing two and sometimes 

 three at a birth. 



The bifurcated antler and the bounding gait observed in the 

 mule deer, are found also to be characteristics of this deer, but 

 they are strictly confined to these two species ; nor is it easy 

 to conceive why this laborious and fatiguing gait has not in 

 the course of time given place to the more easy and enduring 

 running pace of the Virginia deer, which inhabits the same 

 country. 



Both these deer know how to gallop, and do so when not ex- 

 cited and at a moderate speed ; but when alarmed and seeking to 

 make a rapid flight, they strike into the nervous bound, which 

 although rapid at first, can be endured but for a short time, and 

 is particularly laborious on broken ground. 



