The Modern Theory of Instinct 



haps one, would be enough. Gradually, 

 large-sized prey came to be preferred, as re- 

 ducing the number of hunting-expeditions. 

 Then, as successive generations went after 

 bigger game, the dagger-strokes were multi- 

 plied, in proportion to the victim's power of 

 resistance; and, by degrees, the elementary 

 instinct of the outset became the highly- 

 developed instinct of our time." 



To these arguments we may begin by re- 

 plying that the larva's change of diet and the 

 substitution of one morsel for a number are 

 diametrically opposed to what happens be- 

 fore our eyes. The Hunting Wasp, as we 

 know her, is extremely loyal to old customs; 

 she has sumptuary laws which she never 

 transgresses. She who fed on Weevils in 

 her youth puts Weevils and naught else in 

 her larva's cell; she who was supplied with 

 Buprestis-beetles persists in the fare which 

 she has adopted and serves her larva with 

 Buprestis-beetles. One Sphex must have 

 Crickets; a second, Grasshoppers; a third, 

 Locusts. Nothing is accepted but these par- 

 ticular dishes. The Bembex who hunts Gad- 

 flies revels in them and refuses to do without 

 them, whereas Stizus ruficornis, who fills the 

 larder with Praying Mantes, scorns any other 

 405 



