58 



THE ODD-TOED UNGULATES. 



its opposite side, which rose almost perpendicular 

 to a height of six or seven hundred feet. They 

 reached its crest at full gallop in the twinkling of 

 an eye, and without pausing an instant disappeared 

 again, leaving us wondering and amazed at their 

 marvellous agility. I had often seen their paths 

 leading up hill-sides which a man could scarcely 

 climb; but till now that I had witnessed a specimen 

 of their powers with my own eyes, I had scarcely 

 believed them possessed of a nimbleness and clever- 

 ness of foot that would not discredit a chamois." 

 — Across Patagonia, chap, xvii.] 



GEOGRAPHICAL DISTRIBUTION AND DESCENT 

 OF THE ODD-TOED UNGULATES. 



The present Geographical Distribution of 

 the Perissodactyla would be altogether unin- 

 telligible if the relations to the extinct types 

 did not shed some light upon the question, 

 without, however, solving all difficulties. We 

 must trace the stems of the different families 

 back to their deepest roots, in order to obtain 

 some fairly valid indications on the subject. 



The Rock-badger Family [Hyracida) is an 

 essentially African type, which, however, has 

 advanced further east and has spread into 

 Syria, Palestine, and Stony Arabia, where 

 suitable conditions of life offered. Hitherto 

 no direct fossil predecessors of this family 

 have been found. But we must here take 

 into consideration the fact that the soil of 

 Africa is precisely that which has as yet been 

 least examined' with reference to palaeontology. 

 On the other hand, we know a pretty large 

 number of fossil Perissodactyla derived from 

 the upper Eocene and Miocene strata (Lophio- 

 therium, Tapirulus, Hyracodon, &c), which 

 approach the Hyracida in size, in the general 

 character of their dentition, and in particular 

 in the structure of their teeth, and which 

 therefore might well be their remote ancestors. 

 The type would accordingly be one that had 

 been very little modified since Eocene times. 



In the case of the Tapirs it is altogether 

 different. They occupy at the present day 

 two widely-distinct centres in the tropics, the 



larger in south America, the other in the 

 Malay Peninsula and on the islands of Borneo 

 and Sumatra; and what is very remarkable, 

 the shabrack-tapir of the Sunda Islands is not 

 so different from the Brazilian tapir as this 

 is from the highly- interesting neighbouring 

 mountain species of Colombia, out of which 

 the genus Elasmognathus has been formed. 

 We find the explanation of this striking 

 phenomenon in the fact that during Eocene 

 times the entire surface of the earth, with the 

 exception of Australia, was inhabited by con- 

 siderable numbers of tapir-like animals, which 

 have indeed been continued down to present 

 times, but have become steadily reduced in 

 numbers while their domains have become 

 more and more limited. These animals, 

 which are distributed by palaeontologists 

 among numerous genera, were represented 

 by different genera on the two sides of the 

 ocean. The genus Lophiodon in Europe, 

 those of Hyrachyus and Helaletes in America, 

 were the ancestors of genera which already, 

 in the Miocene of Europe, approached very 

 near to the true tapirs, while this approxima- 

 tion in America did not become very marked 

 till the close of the Tertiary period. On the 

 other hand, their domain on the mainland of 

 the Old World became contracted much earlier 

 than on the New. Tapirs still existed in 

 Quaternary times in North America, and it 

 was only in the present geological period that 

 they became confined to South America. I 

 would insist especially on the great difference 

 between the original American and Oriental 

 stocks. These two stocks approach one 

 another by a gradual process of development, 

 each for itself and independently of the other, 

 producing at last two species so closely re- 

 sembling one another as the Malayan tapir 

 and the Brazilian anta, which are so widely 

 separated from each other in space. 



The other two families of Perissodactyla 

 now living, the rhinoceroses and the horses, 

 agree in being now entirely restricted to the 

 Old World, while they are both represented, 



