142 EVOLUTION IN THE PAST 



Indeed they appear to have been Httle more than incidental 

 expenses incurred by Nature in her efforts in rhinoceros 

 development. 

 RHINO- The more truly rhinoceros forms, although in advance of 

 CEROSES their Eocene forerunners, were as yet in experimental stages. 

 Some small animals — not so big as Shetland ponies — were 

 toothed somewhat after the manner of modern rhinoceroses ; 

 but they had comparatively long necks, and somewhat 

 resembled ponies in appearance (Hyracodon). They prob- 

 ably roved in herds about the open country ; and as they 

 were footed like the early equines, and were somewhat 

 lightly built, they were doubtless fair gallopers. Fleetness 

 in flight was indeed of importance, for they were too poorly 

 equipped to confront formidable foes. They hved chiefly 

 in North America, and were probably an offshoot of the old 

 Lophiodont family — so rich in affinities. Their career was 

 of no long span. Indeed in the course of the Period they 

 became extinct — wiped out, probably, by the rapidly in- 

 creasing carnivores. Possibly they never developed sufficient 

 speed for the mode of life they had adopted, and their 

 sentinel system may have been defective. It was never- 

 theless enterprising of the little creatures to seek to better 

 themselves by quitting the swamps and thickets of their 

 forefathers. And their untimely fate excites one's sympathy 

 even at this distance of time. 



Other creatures living in Europe and North America were 

 more stoutly built, and more nearly resembled modern 

 rhinoceroses (Cadurcotherium, Metamynodon). They were, 

 however, hornless ; and they also differed from existing 

 forms in being over-toothed and over-toed. They differed, 

 moreover, in habits, for they haunted lakes and rivers. No 

 trace of these aquatic rhino's has been found after this 

 Period. It would seem, therefore, they were no more suc- 

 cessful than their relatives of the plains. 

 yfeThe genius of rhinoceros-life, however, was by no means 

 defeated. In thickly wooded regions in Europe yet other 

 forms were living (Aceratherium) ; and these, in the matter 

 of teeth and toes, were drawing near to rhinoceroses now 

 living. As the creatures were heavily built and hornless, they 



