The Modern Theory of Instinct 375 



lysed ; the ^%'^ laid on its flank will develop in 

 safety. Is that enough ? It is at most but a 

 half of what is absolutely necessary. Another 

 ^%^ is indispensable to complete the future 

 couple and ensure offspring. Therefore, within 

 a few days', within a few hours' interval, a second 

 sting must be given, as successful as the first. 

 In other words, the impossible has to be repeated, 

 the impossible raised to the second degree. 



Let us not be discouraged yet ; let us sound 

 the uttermost depths of the problem. Here is 

 a Wasp, some precursor, no matter which, of 

 our Ammophila, who, favoured by chance, has 

 twice and perhaps oftener succeeded in reducing 

 the prey to that state of inertia which the rear- 

 ing of the ^%% imperatively demands. She does 

 not know, does not suspect that she inserted 

 her sting opposite a nerve-centre rather than 

 elsewhere. As there was nothing to prompt her 

 choice, she acted at random. Nevertheless, if 

 we are to take the theory of instinct seriously, we 

 shall have to admit that this fortuitous action, 

 though a matter of indifference to the insect, 

 left a lasting trace and made so great an impres- 

 sion that, henceforth, the cunning stratagem 

 which produces paralysis by attacking the 

 nervous centres is transmissible by heredity. 

 The Ammophila's successors, by some prodi- 

 gious privilege, will inherit what the mother did 



