200 NEW YORK ZOOLOGICAL SOCIETY. 



THE DEER. 



In contrast to this probable African origin of the Bozndae, there 

 is little doubt that the Cervidae, or deer family, achieved its 

 development in Eurasia, with an important outlying group on 

 this continent, which, springing from some early Eurasian ances- 

 tor, developed into the American deer, Odocoileus. 



There are in America five genera of this family. The first 

 two, the moose, Alces, and the caribou, Rangifer, are circumpolar 

 in distribution. Being animals of large size and great endurance, 

 they can and do make long migrations, the moose rarely and only 

 when impelled by danger or failing food supply, and the caribou 

 at regular intervals. It is consequently not surprising to find a 

 close resemblance between the Old and New World species of 

 each genus. 



Both the moose and caribou may have developed in some 

 as yet unknown subarctic land. In fact these two genera seem to 

 afford the only evidence from the fauna of North America in 

 support of the theory of the boreal continent. Of the two, the 

 caribou shows, in its structure, more adaptation to Arctic condi- 

 tions. 



Of the American moose only two species are known, one of 

 limited distribution in southern Alaska, A. gigas, and the other, 

 A. americanus, ranging from the limit of tree growth in western 

 and northern Alaska to Nova Scotia on the Atlantic coast, and 

 just entering the United States at several points along its north- 

 ern boundary. It is a larger and finer animal than its Eurasian 

 relative. This, too, holds true of the caribou. 



We have in the American Pleistocene deposits a mooselike 

 form known as Cervalces, with complex antlers which are highly 

 suggestive of those of the giant Alaskan moose. This animal 

 was closely related and possibly ancestral to the moose, in which 

 case the moose may have developed in the northern part of the 

 continent and crossed into Eurasia. More probably it represents 

 another and somewhat aberrant species of moose, coming in at 

 the same time from northern Siberia or other boreal lands. 



In the genus Rangifer we have a greater variety of types, and 

 the species fall naturally into two groups : barren ground caribou 

 and woodland caribou. 



The first has five species : R. granti, of the Alaskan Peninsula on 

 the west ; R. stonei, of the Kenai Peninsula and adjoining main- 

 land (the handsomest of barren ground caribou) ; the typical A'. 



