WASPS, SOCIAL AND SOLITARY 



In a second nest to which food was being carried, we 

 found four caterpillars and a larva about three days 

 old, all the conditions being like those in the other ex- 

 ample. Evidently the larva had been fed from day to 

 day, since four or five days must have elapsed since the 

 making of the nest. 



Westwood states that Ammophila, when she has cap- 

 tured her prey, walks backward, dragging it after her;* 

 but in all the cases that came under our notice she went 

 forward, the caterpillar being grasped near the anterior 

 end, in her mandibles, and either lifted above the ground 

 or allowed to drag a little if long and heavy. It is usually 

 held venter up, but in one case, in which the wasp, 

 while carrying it to her nest, frequently laid it down 

 and picked it up again, it was held with the venter down 

 or up indifferently. 



The all- important lesson that Fabre draws from his 

 study of the Ammophiles is that they are inspired by 

 automatically perfect instincts, which can never have 

 varied to any appreciable extent from the beginning of 

 time. He argues that deviation from the regular rule 

 would mean extinction. For example, if the wasp should 

 sting ever so little to one side of the median line the 

 prey would be imperfectly paralyzed and the egg would 



1 Iiitroductioti to Modern Classification of Insects, ii, 189. 

 52 



