200 A PHILOSOPHER WITH NATURE 



that the shells are still occupied by molluscs, then 

 they stay close by the opening and wait till the snail 

 dies, which generally occurs soon after the beginning 

 of the imprisonment and the strict watch. Upon 

 this the small crab pulls out the carcase, devours it, 

 and moves into the lodging himself. All this is 

 said by other observers to be partly the result of 

 inherited instinct and partly the result of the mind 

 working in response to the call of urgent needs. 

 It is doubtful, however, whether we know all that 

 we think we do about the workings of mind in young 

 animals in such circumstances. The more the 

 subject- is closely studied the less the observer finds 

 himself inclined to accept ready explanations. The 

 mind of young animals contains much that is very 

 difficult to explain with our existing knowledge. 

 Even in the case of the human child, all the present 

 tendency of study is to show that it contains more 

 than we recently would have found it possible to 

 believe. 



