92 REPRODUCTION 



as though he had eaten his own tail and digested it. The 

 tail finally disappears entirely. 



The inside changes are even more wonderful. The 

 intestine, coiled like a watch spring, in which he digested 

 vegetable food, becomes more straight, and becomes suited 

 to animal food. The gills by which he got oxygen from 

 the water gradually disappear, while deeper in his body 

 is developing a pair of lungs into which he takes air 

 through the nostrils. The blood vessels from the heart 

 change so they can take proper care of this new kind of 

 supply of oxygen. The frog doesn't take a vacation during 

 this time. He has to capture food, and must keep his wits 

 about him every minute so that some otner animal will not 

 capture him. It is really a remarkable performance. It is 

 as though a gasoline launch were gradually changed into 

 an electric automobile, which could run either on land 

 or in water, and during the whole of the transformation 

 was a perfectly usable vehicle! 



