SHORT STUDIES OF BATRACHIANS. 349 



undertake it at all, and I am led to believe that the intelli- 

 gence of the wood-frog has been increased by its terres- 

 trial environment, and that it should be ranked with the 

 common toad, which has already been shown to possess 

 much cunning. In other words, the wood-frog has been 

 forced to search for its food to a greater degree than the 

 aquatic species have been, and hunger is probably the 

 most effective stimulus to the growth of intelligence. 



The salamanders, in the same way, by their active 

 movements, wandering disposition, quickness of hearing, 

 and other minor characteristics, give evidence of greater 

 intelligence than that possessed by frogs. This I can 

 state of them, however, as but little more than an impres- 

 sion ; for my efforts to prove them possessed of much 

 cunning were not successful. The purple salamander, it 

 is true, fights when captured, curving its back and snap- 

 ping viciously. This no frog ever does. The common 

 spotted triton (Diemyctdus) becomes quite tame when 

 kept in an aquarium, and, as I found, is soon able to de- 

 termine the difference between a fly held against the 

 glass and one held over the water. I frequently held a 

 fly against the glass and very near the triton ; bat it 

 took no notice of it, after one or two efforts to seize it, 

 but would follow my hand, and, when the fly was held 

 over the surface of the water, the triton promptly leaped 

 at and seized it. This is, indeed, but meager proof of 

 intelligence, but seems to show, I think, that a salaman- 

 der is more cunning than the generality of frogs, but not 

 the equal of the common toad. 



My observations lead me to conclude that the habits 

 of an animal have much, if not all, to do with the intel- 

 lectual capacity it possesses. Frogs, as a class, are not 

 migratory. They frequent a given pond or stream, and, 

 sustained by the insect-life that comes to them, but is not 



