THE TERTIARY PERIOD. 247 



teeth were much as in the cat family generally, but in minute de- 

 tails they resembled most nearly those of the lynx. 



The dog family (Canidce) was much more fully represented 

 than the last, not less than four species having already been des- 

 cribed by Leidy. Canis Haydeni was a wolf of much larger size 

 and more robust form than any now in existence. Another species 

 was also slightly larger than any now living. Leidy calls it Canis 

 rarus, and considers it a near relative if not actual projenitor of our 

 present wolf (Canis occidentalis}. Cotemporary with these large 

 species, and inhabiting the same localities, were two of small size. 

 One of these, called Canis temerarius, was intermediate in form 

 between our prairie wolf and red fox. A still smaller species, more 

 fox than wolf, was about the size of the swift (Cants velooc). 



From the preceding it is apparent that many forms of mammal- 

 ian life culminated in the number of species and the size of individ- 

 uals during the Pliocene epoch. The conditions during those 

 times must have been exceedingly favorable to the development of 

 mammalian -life. Not the- least remarkable is it that most of those 

 animal forms which are now regarded as most useful to man were 

 the most numerous and best represented during an epoch when, so 

 far as we now certainly know, he had not become an actor on the 

 stage of the world. At least no undoubted monuments of his pres- 

 ence in the world during Pliocene times have been preserved in 

 geological history or tradition. The alleged special servants of 

 man, however, were present during the Pliocene epoch in extraor- 

 dinary numbers. Even the mastodon might have been made as 

 serviceable as the elephant was in historic times. There is no good 

 reason to doubt that the great Niobrara elephant (E. imperator} 

 might have been trained to toil as successfully as the species now 

 living in Asia and Africa. Some of the great number of species of 

 the camel family could certainly have been made as useful as the 

 modern " ship of the desert " Even the horse family culminated 

 during those times in the number of species. The fifteen species 

 already described from the Pliocene, were probably only a small 

 fraction of the kinds that then existed. If the three-toed H^/trion 

 horses were not adapted to the service of man, some of the many 

 species of Protohippus and Equus certainly could have been util- 

 ized. We may, therefore, abandon the idea that the development 

 of animal life was designed by the Supreme Intelligence solely for 

 the gratification and use of man. This may have been one pur- 



