58 Prof. Carl Vofft on some Darwinistic Heresies. 



"& 



upon the other characters, that the African horses, the zebras, 

 have been distinguished, under the name of Hippotiyris, from 

 the other horses. Now-a-days we have indigenous Solipedes 

 only in the Old World : those* of America have been intro- 

 duced from Europe at a comparatively very recent historical 

 date ; but in the Quaternary epoch herds of indigenous horses 

 traversed the plains of America as they traversed those of the 

 Old World. 



We now know the phylogeny of the American Solipedes 

 better than that of the Solipedes of the Old World ; we know 

 how tlie feet and the teeth have been gradually transformed 

 from Eocene to Quaternary times, wlien the genus Equus 

 existed on both sides of the Atlantic Ocean. 



Now this genus, which is so uniform, originates from two 

 very different stocks j it is of diphyhtic origin. 



By arranging parallel to one another the lines of descent 

 formed by the genera indicated by paleontologists in America 

 and Europe, and placing the genera opposite each other in the 

 order of the strata, we find, in fact, that we cannot identify 

 any of the genera living on this side of the water during the 

 Eocene, Oligocene, and Miocene epochs with the genera 

 living in America at the same epochs. The LopMotheria, 

 Palceotheria^ Anchitheria, and Hipparionts of the Old World 

 are different from the Eohippi^ Orohippi, Epihipjn, and Anc- 

 liij>pi which mark the same epochs in the New World ; and 

 it is a remarkable thing, to which we shall revert, that the 

 diflerences are the greater as we ascend towards the supposed 

 stocks in the older Tertiary strata. It is only in the Pliocene 

 and Quaternary deposits that we find on both sides of the 

 ocean the identical genera Hippotherium^ Protohippus^ and 

 finally EquuSy the definitive term. 



Let us bring these facts together a little in order to draw 

 the conclusions which flow from them. The ancestors of the 

 horses of one side of the ocean were unable to generate de- 

 scendants on the other shore ; there was therefore an insur- 

 mountable obstacle, the sea ; the two continents must have 

 been separated at least from the Eocene epoch. This con- 

 clusion is confirmed by the study of the other series of descent 

 of terrestrial Mammalia with which we are more or less 

 acquainted — the pigs, the ruminants, the camels, and the 

 rhinoceroses of the Old World originate from stocks and pass 

 through genetic stages different from those of the corresponding- 

 series of the new continent. 



Geological geography, that is to say the delimitation of the 

 ancient continents and seas at difterent geological epochs as 

 taught to us by geology, must therefore occupy an important 



