154 ORIGIN OF LIFE IN AMERICA 



other mammals apparently had their original home in this 

 continent. Peccaries and tapirs, which, as we know, require 

 a hot and moist climate, lived as far north as Pennsylvania 

 even during the time when vast glaciers were supposed to have 

 covered the whole of Canada and a substantial slice of the 

 United States. We are told that the fauna of .this period 

 clearly reveals the state of the climate. If the remains of the 

 animals above referred to indicate anything, they show us un- 

 doubtedly that the climate was mild, with an abundance of 

 vegetation and animal life. In common with most other geo- 

 logists, Dr. Hay believes that the climate of the Glacial 

 Epoch must have been cold in North America, because he 

 assumes the certain existence of vast ice -masses at that time 

 even in New York, in Indiana and in Missouri. If we deal 

 with this climatic problem from an independent standpoint 

 and endeavour to reconstruct the conditions prevailing during 

 the Glacial Epoch from purely faunistic evidence, our con- 

 clusions cannot point to the prevalence of an exceptionally 

 cold climate. Proof of the existence of a cold climate in the 

 United States during the Pleistocene Period seems to be fur- 

 nished, says Dr. Hay,* by the occurrence of the three genera 

 of mammals, Rangifer, Bootherium and Symbos. 



The name Bootherium is now applied to an extinct large 

 sheep-like creature, viz., B. bombifrons, whose remains have 

 been discovered in Pleistocene deposits of Kentucky. Accord- 

 ing to Dr. Kowarzik (see p. 7), Bootherium was probably 

 the direct ancestor of the northern genus Ovibos, which has 

 never been found in any Pleistocene beds in the United States. 

 Bootherium can scarcely be claimed as an exponent of a 

 cold climate, because it has never lived north of the United 

 States. The latest discoveries seem to indicate that a number 

 of sheep-like animals originated in the United States towards 

 the latter part of the Pliocene Period, and left their remains 

 in various parts of the country. Thus the extinct Euoera- 

 therium, first identified by Dr. Sinclair and Mr. Furlong from 

 a cave in California, and Preptoceras from another Californian 

 cave, are both allied to Bootherium and Ovibos. Hence Ovibos 

 is the sole member of this group which has survived, having 



* Hay, O. P., " On the Changes of Climate," p. 372. 



