178 



HIGH SCHOOL ZOOLOGY. 



found, vnth complete front teeth, and separate metapodials. The 

 descendants of these must have made their way into the Old World by a 

 bridge which existed between North America and Asia, and which after- 

 wards subsided so as to form Behring Straits. 



Like the CamelidcB, the pigmy deer of Java and West Africa ^T'mr/M- 

 lldm) have tusk-like upper canines in the males and only three compart- 

 ments of the stomach ; their metapodials are less completely coalesced 

 than in the camels. In size and in the possession of tusk-like canines, 

 the musk-deer of Central Asia (Moschus) resemble the pigmy deer, but 

 the male has a peculiar musk-gland on the skin of the ventral surface. 



A fourth group is that of the Girafifes (Camdopardalis) an African 

 form much nearer the typical Ruminants than any of the foregoing. 

 They differ from them both in the general form, and in the horns, which 

 are skin-bones covered with soft skin, the most primitive of the horns 

 of the ruminants. ^ 



32. It is according to the nature of these structures, that we subdivide 

 the typical Ruminants into the hollow-horned (Cavicornia) and the ant- 

 lered forms (CervidceJ. In the former, projections of the frontal bones 

 form the so-called cores, which are covered with the variously-shaped but 

 usually unbranched horn, in the latter, the frontal bones bear the ant- 

 lers, with an inters^ening ring of bone, the "rose," where the antlers are 

 broken off each year. The antlers are only covered by skin (the velvet) 

 while they are undergoing formation ; that process complete, the velvet 

 is rubbed off, and the polished bone exposed. We noted that, in several 

 of the preceding families, only the males have tusk-like upper canines ; 

 in these forms, also, it is of common occurrence that tlie males only 

 should have the weapons of offence and defence in the shape of horns or 

 antlers. Among the Cerpidce, the Reindeer or Caribou (Puingifer) is 

 singular in that both sexes have antlers, which like those of the Moose 

 (Alces) are broad and palmated in form. Those of the Stag^'C Can- 

 adensis) as well as of the Virginia deer (Cariacus virginianus) carry 

 rounded branches. 



Among the Cavicornia, the Prong-hom of the Western prairies {Antih- 

 capra americana) is the only form with a tendency to branching of 

 the core. It comes nearest the Cervidoi in this respect, as well as in the 

 fact that it casts its horns at intervals. It is usually classified with the 

 Antelopes, a sub-family of the Cavicornia, whose headquarters are 

 Africa, bu'_; which are less numerous in Europe and Asia. The only 



