180 CREATIVE EVOLUTION 



something quite different, we believe, from an intelligent 

 effort). But the former are probably wrong when they 

 make the evolution of instinct an accidental evolution, 

 and the latter when they regard the effort from which 

 instinct proceeds as an individual effort. The effort 

 by which a species modifies its instinct, and modifies 

 itself as well, must be a much deeper thing, dependent 

 solely neither on circumstances nor on individuals. 

 It is not purely accidental, although accident has a 

 large place in it ; and it does not depend solely 

 on the initiative of individuals, although individuals 

 collaborate in it. 



Compare the different forms of the same instinct 

 in different species of Hymenoptera. The impression 

 derived is not always that of an increasing complexity 

 made of elements that have been added together one 

 after the other. Nor does it suggest the idea of steps 

 up a ladder. Rather do we think, in many cases at 

 least, of the circumference of a circle, from different 

 points of which these different varieties have started, 

 all facing the same centre, all making an effort in that 

 direction, but each approaching it only to the extent of 

 its means, and to the extent also to which this central 

 point has been illumined for it. In other words, instinct 

 is everywhere complete, but it is more or less simpli 

 fied, and, above all, simplified differently. On the other 

 hand, in cases where we do get the impression of an 

 ascending scale, as if one and the same instinct had 

 gone on complicating itself more and more in one 

 direction and along a straight line, the species which 

 are thus arranged by their instincts into a linear series 

 are by no means always akin. Thus, the comparative 

 study, in recent years, of the social instinct in the 

 different apidae proves that the instinct of the meli- 



