The Evolution 01 the Horse 



parion for the reason that it is devoid of some of 

 the peculiarities of that form — peculiarities which 

 tend to show that the European Hipparion is 

 rather a member of a collateral branch, than a 

 form in the direct line of succession. Next, in 

 the backward order in time, is the Miohippus, 

 which corresponds pretty nearly with the . 1 nchi- 

 thcrium of Europe. It presents three complete 

 toes — one large median and two smaller 

 lateral ones; and there is a rudiment of that 

 digit, which answers to the little ringer of the 

 human hand. 



The European record of the pedigree of the 

 horse stops here; in the American Tertiaries, on 

 the contrary, the series of ancestral equine forms 

 is continued into the Eocene formations. An 

 older" Miocene form, termed Mesohippus, has 

 three toes in front, with a large splint-like rudi- 

 ment representing the little finger; and three toes 

 behind. The radius and ulna, the tibia and the 

 fibula, are distinct, and the short crowned molar 

 teeth are anehithcrioid in pattern. 



But the most important discovery of all is 

 the Orohippus, which comes from the Eocene, for- 

 mation, and which is the oldest member of the 

 equine series, as yet known. Here we find four 

 complete toes on the front-limb, three toes on 

 the hind-limb, a well-developed ulna, a well- 

 developed fibula, and short-crowned grinders of 

 simple pattern. 



Thus, thanks to these important researches, it 

 has become evident that, so far as our present 

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