THE UNGULATA, OR HOOFED ANIMALS. 131 



down to a mere remnant of the fifth meta- 

 carpal. But it is of use almost exclusively to 

 the fourth toe, and has grown into one piece with 

 its neighbour, 4. Kowalewsky thinks that he may 

 safely affirm that the inadaptive forms like the 

 Anoplotherium had, as a rule, a very short term 

 of existence, and differentiated within narrower 

 limits ; and that the adaptive forms possessed the 

 more advantageous predisposition of being further 

 developed, as is shown by their preservation and 

 transformation up to the present time. 1 



The first incomings of the Hoofed animals are 

 as yet lost in the same obscurity as those of the 

 other orders ; they are found variously developed 

 as early as the Lowest Eocene strata. A single 

 genus, indigenous both to the Old and the New 

 World, possesses five toes on the fore and hind 

 limbs, but already showing an inclination to odd- 

 hoofedism, if we may use the rather strange ex- 



1 Filhol has uttered a decided protest against the genus 

 Anoplotherium. It is said to be plentifully represented in the 

 Upper Eocene by a number of sub-genera and species. Filhol 

 asks us to consider that the sudden disappearance of the Ano- 

 plotheridae, without leaving identifiable descendants, may as well 

 be the result of emigration as of a general dying out. Still 

 Kowalewsky's opinion has the advantage of being not merely a 

 supposition, but one based upon a very plausible scientific 

 deduction. 



