The Pronghorn Antelope 99 



the westward-moving traveller left the green bot- 

 tom-lands of the Mississippi, and from thence 

 across to the dry, open valleys of California, and 

 northward to Canada and southward into Mexico. 

 It has everywhere been gradually thinned out, and 

 has vanished altogether from what were formerly 

 the extreme easterly and westerly limits of its 

 range. In dealing with the mule-deer I have 

 already explained how unequal the rates of exter- 

 mination of the different kinds of big game have 

 been in different localities. Each kind of big 

 game has had its own peculiar habitat in which it 

 throve best, and each has also been found more 

 or less plentifully in other regions where the cir- 

 cumstances were less favorable ; and in these 

 comparatively unfavorable regions it early tends 

 to disappear before the advance of man. In con- 

 sequence, where the ranges of the different game 

 animals overlap and are intertwined, one will dis- 

 appear first in one locality, and another will dis- 

 appear first where the conditions are different. 

 Thus the whitetail deer had thrust forward along 

 the very narrow river bottoms into the domain of 

 the mule-deer and the prongbuck among the 

 foot-hills of the Rocky Mountains, and in these 

 places it was exterminated from the narrow strips 

 which it inhabited long before the mule-deer 

 vanished from the high hills, or the prongbuck 

 from the great open plains. But along great 



