76 THE DARWINIAN THEORY 



Pliocene age, showing that they are comparatively 

 recent immigrants into that continent, perhaps by 

 means of the Behring Straits again. The climate 

 even now is much milder than on the north-east of 

 America, and perhaps was warm enough in late 

 Pliocene times to allow emigration of tapirs, which 

 were driven south to the swampy forests of the 

 Malay region. 



Conclusion. — On the whole, then, the evidence 

 afforded us by fossils is not so complete as we 

 should wish, and we have seen that from the 

 necessity of the case this must be so. However, 

 evidence is steadily accumulating, and such evidence 

 as we have is not merely favourable, but in some 

 instances remarkably complete. Indeed, since the 

 date of publication of the " Origin of Species," in 

 1859, our knowledge has increased, and evidence 

 has accumulated so markedly, that it has been said 

 by a highly competent authority, that if the doctrine 

 of Evolution had not existed, palaeontologists would 

 have been compelled to invent it as the only possible 

 explanation of the facts determined. Again, we are 

 not aware of the existence of palaeontological facts 

 which can be demonstrated to be inconsistent with the 

 theory ; while the explanation which they afford of new 

 and previously unstudied problems, such as some of 

 the questions of geographical distribution we have 

 touched upon, is evidence of a strong nature in 

 support of the theory. Professor Huxley, with 

 regard to this subject, says : " The primary and 

 direct evidence in favour of Evolution can be fur- 

 nished only by palaeontology. The geological 



