NATURAL HISTORY OP CHINA SOWERBY 353 



to consider the paleontological side of our subject, since this bears 

 so strongly upon the present distribution of the animals of China. 



It may be taken that a fair amount is known about the fossils 

 that occur in the older formations, since several able paleontologists 

 have been devoting their time to this branch of study. A geological 

 museum has been started in Peking, as well as a geological survey 

 of the whole of China, and already a considerable amount of valuable 

 material upon which experts are now working has been gathered. 

 It is the more recent formations, however, that most interest us here, 

 since it is from them that we may find out when the animals we 

 now know to exist in the country arrived there, and also what forms 

 immediately preceded them. Unfortunately these recent deposits 

 have not as yet been well worked or explored, though some inter- 

 esting results have already been obtained. Thus we learn that the 

 porcupine, now not known to occur north of the Yangtse Valley, 

 once inhabited the province of Chihli, numerous remains of the 

 animal having been found in recent deposits round Peking. Such 

 a discovery is significant, for it shows that at no very distant date, 

 geologically speaking, that part of China had a very much warmer 

 climate than it has now. Couple with this fact my recent discovery 

 in the imperial hunting grounds of northeastern Chihli, of a species 

 of squirrel (Ta?niops) , which belongs to a genus that does not occur 

 elsewhere in China north of Ssuchuan in the west and Chekiang in 

 the east, and it becomes obvious that the forests of west, central, 

 southwest, and northeast China were at one time connected, a belt 

 of heavy vegetation and trees probably extending all the way from 

 Indo-China to the borders of Manchuria. 



While exploring in Manchuria, I secured a specimen of a large 

 bear that could not be classed either with the brown or the black 

 bears of Asia. It was undoubtedly a grizzly, but up to that time 

 the living grizzlies were supposed to be confined to North America. 

 I was able to show that this bear was indeed a true grizzly, and also 

 that there were other grizzlies in Asia. This very clearly shows 

 how the grizzlies came to be present in North America, for these 

 Asiatic forms are undoubtedly connecting links between the pre- 

 historic grizzlies or cave bears of England and western Europe, 

 which became extinct only after the fourth glaciation, and the 

 living grizzlies of North America. The only way in which the 

 latter could have acquired their present distribution was by the mi- 

 gration or, perhaps it would be better to say, the gradual spread, 

 of their ancestors from Europe across Siberia or central Asia to 

 the American continent by way of the land bridge that once existed 

 where the Bering Sea now lies. 



This land bridge was a very important factor in the present 

 distribution of the animals of both America and the Eurasian land 



