14 THE FOUNDATIONS OF ZOOLOGY 



use strengthens muscles and increases their aptitude for doing 

 their work, but as muscles may also be strengthened by massage, 

 their improvement by use is no more than their nature might 

 have led us to look for; nor do we find any more difficulty in 

 attributing this beneficial response to nature than we find in the 

 same explanation of the house-hunting actions of crabs. 



All who have to do with animals admit that training can do 

 no more for them than to make the best of their natural capa- 

 city, for they differ greatly in power to profit by experience; and 

 the nature of each species sets impassable bounds to the power 

 of individual animals to improve by practice. No one hesitates 

 to attribute to deficient structure the inability of idiots to learn, 

 and all admit that men of genius are born and not made, yet 

 many hesitate to confess that their own more commonplace 

 capacity for profiting by practice and growing wiser with experi- 

 ence is strictly limited by their nature, although this may be 

 quite obvious to others. All know too well also that a dose of 

 alcohol may make a man remember what never happened outside 

 his own disordered brain, and perform responsive actions which, while 

 criminal, might be prudent and commendable if the remembered 

 experience were not a delusion ; although the effects of contact with 

 the world are usually far too complicated and diversified to be artifi- 

 cially imitated. As we are quite unable to tell with any minute 

 accuracy what an animal with capacity for training will do under 

 a stimulus, we must rely upon indirect evidence to show what the 

 real significance of experience is. 



If a chick is stung by the first honey-bee it catches, its future 

 actions may be adjusted to the natural law that bees are danger- 

 ous; but if, before it is stung, it has captured and eaten stingless 

 drones, it may act in accordance with the wider law that while 

 bees are good for food some are dangerous. A careful observer, 

 Mr. Gilman Drew, tells me that the chicks that are most destruc- 

 tive to bees pick out the drones, and he believes that these are 

 the chicks which, before they were stung, learned to catch and 

 eat bees, and that they have afterwards learned to let the sting- 

 ing workers alone. 



If slight differences in the mere order of events which are 

 otherwise so much alike may lead to such differences in the con- 



