INTELLIGENCE IN ANIMALS. 167 



ling?'" This explanation wonld go far, it would 

 seem, to do away with the idea that the rats in this 

 case had reasoned, seeing that if they recognised the 

 presence of water by the sense of hearing, their action 

 in biting their way through to what they wanted 

 would correspond precisely with what we have been 

 taught (erroneously, in all probability, but that is a 

 detail) to regard as instinctive. The narrator, how- 

 ever, did not read Dr. Darwin's reply in this sense. 

 " It may be conceded/ 7 he says, " that this explana- 

 tion is the most probable, and if it be the true one, 

 we have an example of an animal using his senses to 

 obtain the data for a process of reasoning leading to 

 conclusions about which he is so certain that he will 

 go to the trouble of cutting through a considerable 

 thickness of lead. Obviously man could do no more 

 under the same conditions." If the rats had shown 

 in their boring operations some special aptitude for 

 securing most conveniently, with the least possible 

 overflow, the water they required, this would be a 

 just inference. But as we know no more than that, 

 having found, probably by the sense of hearing, that 

 water was present in the pipe, they bored their way 

 through to reach it, we have in reality no more proof 

 of reasoning power than is afforded by the familiar 

 action of mice biting their way through the wooden 

 or card casings of boxes of edibles they like, of whose 

 presence within such boxes the sense of smell has 

 convinced them. 



This objection is well put by Mr. Henslow in a 



