IP n i:ix OH EVOLUTION m 



upon the doctrine of evolution, it appeared to me 

 that the Anchithcrit'ni, the Hipparion, and tin- 

 modem horses, constitute a series in which tin* 

 modifications of structure coincide with the order 

 of chronological occurrence, in the manner in 

 which they must coincide, if the modern hois, s 

 really are the result of the gradual metamor- 

 phosis, in the course of the Tertiary epoch, of 

 a less specialised ancestral form. And I found 

 by correspondence with the late eminent French 

 anatomist and paleontologist, M. Lartet, that he 

 had arrived at the same conclusion from the 

 same data. 



That the Anchitherinm type had become meta- 

 morphosed into the Hipparion type, and the 

 latter into the Equine type, in the course of 

 that period of time which is represented by the 

 latter half of the Tertiary deposits, seemed to 

 me to be the only explanation of the facts for 

 which there was even a shadow of probability. 1 



And, hence, I have ever since held that these 

 facts afford evidence of the occurrence of evo- 

 lution, which, in the sense already defined, may 

 be termed demonstrative. 



1 I 11. so the word " type " because it is highly probable that 

 many forms of Anchit1icrium~\\kc and ffipparion-like animals 

 existed in tli i Miocene and Pliocene epochs, just as many sjx-cii s 

 of th> hi.rs*- tribe exist now ; and it is highly improbable that 

 the particular species of Anchithcrium or Hipparion, which 

 h.ippfii to have been discovered, should he precisely those 

 which have formed part of the direct line of the horse's 

 pedigree. 



