The Geological Evidence of the Origin of Species by 

 Evolution. By Prof. Chaeles Callaway. 



[Read before the Albany Institute, December 16, 1873. J 



To prevent misunderstanding, let me at starting dis- 

 tinctly define what I propose to do. I express no opinion 

 on Darwin's hypothesis of the origin of species by natural 

 selection. Evolution does not necessarily involve natural 

 selection. All I contend for is evolution in contradistinc- 

 tion from separate creation. Then, too, I do not pretend 

 to present a complete case. I retain myself as counsel to 

 examine only one class of witnesses, the races of extinct 

 beings who being dead yet speak. 



Much will depend on our answer to the preliminary 

 question, " What is a species?" Naturalists have gene- 

 rally agreed that a species is that assemblage of animals 

 or plants the individuals of which are fertile. Distinct 

 species either produce no offspring, or their progeny is a 

 hybrid and is barren. It is not necessary that I should dis- 

 cuss this definition, simply because it is quite inapplicable 

 in the present case. We cannot resuscitate fossil forms 

 and command them to be fruitful and multiply. We must, 

 then, seek some other test, and I confess myself in despair 

 of finding one. Let us assume one ; let us define a species 

 as that assemblage of living forms which agree in the 

 possession of certain characters which are not collect- 

 ively possessed by any other assemblage. I presume no 

 one will object to the substance of that definition. E~ow 

 the unscientific, if there are any here, will ask where is 

 your difficulty ? Is not a horse distinguished from an ass 

 by certain characters, and is there any likelihood of con- 



