Geological Evidence of Origin of Species. 213 



The same law also holds good with regard to the Mollusca and 

 other classes of invertebrata. The younger Tertiary de- 

 posits contain shells so closely resembling those inhabiting 

 the same districts, that a proportion of them are even identi- 

 cal in their species. Indeed, the divisions of the Tertiary 

 from the Eocene to the Pleiocene are based upon the per- 

 centage of recent species which they contain. Numerous 

 additional illustrations might be adduced, did my space 

 permit. The evolutionist thinks that the law thus briefly 

 illustrated is more naturally explained by lineal descent than 

 by separate creation. 



I have said that living forms closely resemble the fossils 

 of epochs immediately preceding the recent. But as we re- 

 cede through the Tertiary periods, the resemblance grows 

 weaker and weaker, though even in the Eocene the types 

 of our living orders are more or less distinctly represented. 

 But when we go back into the Mesozoic epochs, the diver- 

 gence becomes much greater. Jurassic plants and animals 

 have little resemblance to those now inhabiting the same 

 zoological province. Indeed, we find in Europe a fauna 

 and flora of decidedly Australian facies. The mammalia 

 are mostly marsupial, aud of plants, cycads and ferns pre- 

 dominate. The plants of North America have their fossil 

 congeners in the Miocene of Europe. Now such facts as 

 these are in perfect harmony with the evolution hypothesis. 

 Since the Jurassic period great physical changes have oc- 

 curred. Groups of islands have become continents, and 

 continents have doubled and trebled their area. On the 

 other hand, denudation has been grinding down and eating 

 up the laud, or the depression of land has caused its submer- 

 gence. Since that time the foundations of Judaea, Greece 

 and Italy have been laid in the depths of the sea. Sand and 

 mud has been worn down from all continents, deposited in 

 strata miles in thickness, and elevated into the Alps and 

 Himalayas. The floor of a broad sea continuous with the 

 Gulf of Mexico has been elevated to form the western states 



