Up the River of Tapirs 147 



and wedge shape enable them to go at speed through very 

 dense cover. They try to stamp on, and even to bite, a 

 foe, but are only clumsy fighters. 



The tapir is a very archaic type of ungulate, not un- 

 like the non-specialized beasts of the oligocene. From 

 some such ancestral type the highly specialized one-toed 

 modern horse has evolved, while during the uncounted 

 ages that saw the horse thus develop the tapir has con- 

 tinued substantially unchanged. Originally the tapirs 

 dwelt in the northern hemisphere, but there they grad- 

 ually died out, the more specialized horse, and even for 

 long ages the rhinoceros, persisting after they had van- 

 ished; and nowadays the surviving tapirs are found in 

 Malaysia and South America, far from their original 

 home. The relations of the horse and tapir in the pale- 

 ontological history of South America are very curious. 

 Both were, geologically speaking, comparatively recent 

 immigrants, and if they came at different dates it is al- 

 most certain that the horse came later. The horse for an 

 age or two, certainly for many hundreds of thousands of 

 years, throve greatly and developed not only several dif- 

 ferent species but even different genera. It was much the 

 most highly specialized of the two, and in the other conti- 

 nental regions where both were found the horse outlasted 

 the tapir. But in South America the tapir outlasted the 

 horse. From unknown causes the various genera and 

 species of horses died out, while the tapir has persisted. 

 The highly specialized, highly developed beasts, which 

 represented such a full evolutionary development, died 

 out, while their less specialized remote kinsfolk, which 

 had not developed, clung to life and throve; and this 



