140 CREATIVE EVOLUTION [chap. 



often require appropriate action and a kind of initiative 

 on the part of the larva, there is no sharp line of demarca- 

 tion between the instinct of the animal and the organizing 

 work of living matter. We may say, as we will, either that 

 instinct organizes the instruments it is about to use, or 

 that the process of organization is continued in the instinct 

 that has to use the organ. The most marvelous instincts 

 of the insect do nothing but develop its special structure 

 into movements: indeed, where social life divides the 

 labor among different individuals, and thus allots them 

 different instincts, a corresponding difference of structure 

 is observed: the polymorphism of ants, bees, wasps and 

 certain pseudoneuroptera is well known. Thus, if we 

 consider only those typical cases in which the complete 

 triumph of intelligence and of instinct is seen, we find 

 this essential difference between them: instinct perfected 

 is a faculty of using and even of constructing organized 

 instruments; intelligence perfected is the faculty of making 

 and using unorganized instruments. 



The advantages and drawbacks of these two modes 

 of activity are obvious. Instinct finds the appropriate 

 instrument at hand: this instrument, which makes and 

 repairs itself, which presents, like all the works of nature, 

 an infinite complexity of detail combined with a marvelous 

 simplicity of function, does at once, when required, what 

 it is called upon to do, without difficulty and with a per- 

 fection that is often wonderful. In return, it retains an 

 almost invariable structure, since a modification of it 

 involves a modification of the species. Instinct is there- 

 fore necessarily specialized, being nothing but the utili- 

 zation of a specific instrument for a specific object. The 

 instrument constructed intelligently, on the contrary, 

 is an imperfect instrument. It costs an effort. It is 

 generally troublesome to handle. But, as it is made of 



