II 4 NATURE STUDIES. 



such is the logical dead- wall that awaits the student 

 who turns to the " special creation " theory for an 

 explanation. There is no accounting for a super- 

 natural ^creative fiat ; we cannot give reasons for a 

 "special creation;" in a word, we must, on this 

 theory of nature, simply accept the fact of the frog's 

 existence, and have done with it. But there exists 

 the alternative idea of evolution and descent. What 

 if it be admitted that one species or group of animals 

 arises by natural variation and descent from another 

 group ? What if in the frog's development we are led 

 to see a panorama a moving picture, of the descent 

 of its race? The reasonableness of evolution may 

 thus, I think, become very apparent ; contrariwise, I 

 know of no other rational explanation of the frog's 

 tadpole-stage, and its subsequent development. 



What evolution, then, says is this : the frog is, at 

 first, a fish-like, gill-breathing tadpole, with a fish- 

 heart, because its earliest ancestor was a fish ; and it 

 is interesting to note that the young of some well- 

 known fishes (e.g., dog-fishes) breathe by outside 

 gills. I have a beautiful specimen of two of these 

 young fishes with their outside gills in my museum. 

 Furthermore, the resemblances of the tadpole to the 

 type of some primitive fish do not end with its outside 

 aspect. Mr. F. M. Balfour says the anatomy of the 

 tadpole points to its relations with the living lam- 

 preys, which, as every naturalist admits, must be 

 fishes of a very ancient type. But, secondly, the 

 tailed tadpole becomes four-legged, and it thus 



