226 THE SOLITARY WASPS. 



that it does, in most instances, is to overcome the resistance of 

 its prey. "We believe that the primary purpose of the stinging 

 is to overcome resistance and to prevent the escape of the vic- 

 tims, and that incidentally some of them are killed and others 

 are paralyzed. 



Monteiro saw a combat in which a wasp stabbed a spider right 

 in the abdomen "when it instantly curled up its legs and dropped 

 like dead to the ground." We, ourselves, have often witnessed 

 such fights and the effect of the poison of the wasp is as instan- 

 taneous as an electric shock. The habit of stinging in the 

 ganglion (where that habit is found) has doubtless been de- 

 veloped through natural selection, the power of quickly and ef- 

 fectively reducing a vigorous foe to absolute helplessness being 

 clearly an advantage. With those families that live on creat- 

 ures that are themselves armed with poisonous falces, as in the 

 case of spiders, we see an additional reason why the practice 

 of stinging to disarm them would be beneficial in the struggle 

 for existence; and it may be that we have here a partial clue to 

 the infrequent use of the sting in flycatchers. 



Pompilus scelestus takes a spider much larger than herself, 

 reducing it in a moment to a condition of absolute helplessness. 

 For three or four hours after it is stung it is as limp as a drop 

 of jelly so that it can be dragged to the nest and packed tightly 

 down into its close fitting tomb. Within the next twenty-four 

 hours it recovers, showing that the nerve-center has not been 

 wounded by the lance of the wasp, but only benumbed by the 

 transfusion of the poison. The rapid return to health has no 

 menace for scelestus and no advantage for the spider, since the 

 earth will hold it motionless until its life is ended by the grow- 

 ing larva. 



But what of Sphex and Ammophilat For the first the cica- 

 da or grasshopper is strong and active and it is obviously desir- 

 able to put it into an inert condition as speedily as possible, not 

 only to prevent its escape, but for facility in transporting it. 

 Ammophila has often far to carry her caterpillar, and this, too, 

 through grass and over many a rough road. With a perfectly 



