210 THE ANATOMY OF SCIENCE 



may, however, be due to a tendency of the adult 

 insect to seek the plant to which it has become 

 accustomed in the larval state. 



There are a great many minor observations 

 which seem to indicate the transmission of 

 mental characteristics acquired in a very few 

 generations, although it is possible that each 

 one would be ruled out by a very rigorous exclu- 

 sion of evidence. Darwin believed the story of 

 travelers, that birds in newly discovered islands 

 acquire a fear of man which persists when the 

 islands are once more visited after a number of 

 bird generations. But this idea has since been 

 seriously disputed. 



It is generally believed, by those who raise 

 animals, that a wild strain, such as a strain of 

 wolf in dogs, leads to a number of generations 

 of relatively untamable animals ; but no one has 

 made a really thorough investigation of this 

 belief. I have myself noticed how easily a young 

 dog w^hose ancestors have all been trained to 

 hunt birds is excited by anything with feathers, 

 and relatively uninterested in other forms of 

 wild life; but this may be due to the selection 

 and utilization of a trait already existing in 

 certain canine varieties. 



We know many kinds of creatures who have 



