INTELLIGENCE, ETC., IN LOWER ANIMALS 75 



every animal from every plant has hitherto been sought 

 in vain, so it has hitherto been impossible to frame a 

 definition which while including all instincts shall admit 

 no case of reflex action or intelligence. The most 

 ambiguous cases of all are perhaps to be found in 

 insects, where, as will shortly be explained, our infor- 

 mation is ill-fitted to support precise distinctions. 



Many naturalists entertain some form of what may 

 be called the usi-and-disuse or inherited-memory theory, 

 supposing that the aptitudes of the offspring are 

 influenced by the activities of the parent. Some cling 

 to the belief that habits can be fixed and transmitted, 

 and we must admit that the fixation and transmission 

 of habits might explain a great deal. But all the 

 evidence goes to prove that habits are not inherited at 

 all, and that we must look elsewhere for the origin of 

 instincts. Let naturalists who think differently try to 

 account for the instincts of working bees or ants, which 

 receive their psychical not less than their physical 

 endowment from a long succession of ancestors, none 

 of which worked for their living. Or let them try to 

 explain the instances of spiders, insects, etc., which 

 after egg-laying practise instinctive arts for the defence 

 of their brood, standing over the eggs, carrying them 

 about, blocking the entrance of the burrow, etc. May 

 we not say that it is impossible for the acts of a parent 

 to influence the congenital instincts of offspring which 

 have already lost connection with the mother ? But 

 surely a theory of instinct breaks down which fails to 

 account for the expedients by which the worker-bee, 

 the worker-ant, and the spider provide for the safety 

 of the unhatched brood or for the welfare of the 

 community. 



Darwin's Origin of Species threw a new light upon 



F 2 



