116 ORGANIC EVOLUTION CONSIDERED 



as highly developed as, and " are closely related to 

 Polypterus and Lepidosisen;" if "the earliest known 

 Marsupials may have been as highly organized as 

 their living congeners;" if, in fact, these several kinds 

 of highly organized vertebrates— Fishes, Amphibians 

 and Reptiles — could exist through such long periods 

 of time without making much change or progress, 

 then, indeed, it would seem hopeless to look to any of 

 these as the ancestors of mammals, and, finally, of 

 man. 



Here, then, to begin with, we have a large volume of 

 evidence from Paleontology with regard to the Inver- 

 tebrates and the lower Vertebrates up to and includ- 

 ing Marsupials which negatives the idea of evolution. 

 This leaves only the question as to the origin of the 

 higher Vertebrates to be considered from the known 

 facts derived from their fossil remains. 



With regard to them Prof. Huxley says in the 

 same address : " But when we turn to the higher Ver- 

 tebrata, the results of recent investigations, however 

 we may sift and criticise them, seem to me to leave a 

 clear balance in favor of the doctrine of evolution of 

 living forms one from another. Nevertheless, in dis- 

 cussing this question, it is very necessary to discrimi- 

 nate carefully between the different kinds of evidence 

 from fossil remains which are brought forward in 

 favor of evolution. 



"Every fossil which takes an intermediate place 

 between forms of life already known, may be said, so 

 far as it is intermediate, to be in favor of evolution, 

 inasmuch as it shows a possible road by which evolu- 

 tion may have taken place. But the mere discovery 

 of such a form does not, in itself, prove that evolu- 

 tion took place by and through it, nor does it con- 

 stitute more than presumptive evidence in favor of 

 evolution in general. Suppose A, B, C to be three 



