The Evolution of the Horse 



horse, is a good-sized and permanent tooth, while 

 the grinder which follows it is but little larger 

 than the hinder ones. The crowns i >f the grinders 

 are short, and though the fundamental pattern 

 of the horse-tooth is discernible, the front and 

 back ridges are less curved, the accessory pillars, 

 arc wanting, and the valleys, much shallower, 

 are not filled up with cement. 



Seven years ago, when I happened to be look- 

 ing critically into the bearing of palaeontological 

 facts upon the doctrine of evolution, it appeared 

 to me that the Anchitherium, the Hipparion, and 

 the modern horses, constitute a series in which 

 the modifications of structure coincide with the 

 order of chronological occurrence, in the manner 

 in which they must coincide, if the modern horses 

 really are the result of the gradual met aim >rphosis, 

 in the course of the Tertiary epoch, of a less 

 specialized ancestral form. And 1 found by corres- 

 pondence with the late eminent French anatomist 

 and palaeontologist, M. Lartet, that he had arrived 

 at the same conclusion from the same data. 



That the A nchitherium type had become meta- 

 morphosed into the Hipparion type, and the 

 latter into the Equinetype* in the course of that 



* I use the word "type" because it is highly probable 

 that many of the forms of Anchitherium-like and Hipparion- 

 like animals existed in the Miocene and Pliocene e] 

 just as many species of the horse tribe exist now; and it is 

 highly improbable that the particular species of Anchitherium 

 or Hipparion, which happen to have been discovered, should 

 be precisely those which have formed part of the direct line 

 of the horse's pedigree. 



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