$6 INSECT BEHAVIOR 



is a long-legged creature with a good plump body, soft and unpro- 

 tected. With a little chloroform, I anaesthetize it, just long enough 

 to keep the creature quiet. As soon as it is still, I clip its legs off 

 quite short, then with a very slender needle I stab the cephalothorax 

 in two places, once from above, once from below. My object is to 

 reach the ganglions mentioned above, thereby, injuring them with my 

 needle and producing a sort of paralysis in the spider. The experi- 

 ment works well enough. The victim quivers for a moment, then 

 lies motionless. With my crude sting, represented by the needle, I 

 have imitated as closely as possible the methods employed by the 

 parent wasp in preparing food for her offspring: 



Now I place the spider in the cell just under the suspended un- 

 hatched egg of the wasp and await developments. In two days the 

 young wasp emerges from the shell, and hangs head down, still 

 attached at its anal segment to the cell wall. For several hours I 

 keep close watch, during which time it pays no attention to the para- 

 lyzed spider. It scorns my work and the repast I have prepared and 

 hangs helplessly, its mouth sucking rhythmically at the air. Now I 

 move the spider so that one of the stab wounds in its body comes in 

 contact with the larva's mouth. It responds frantically, like a crea- 

 ture dying of thirst, to the liquid that oozes from the wound. It 

 fastens itself by the mouth to its victim and there it clings like a 

 suction pad, its entire body rippling as it drains the spider's life. 



Much to my surprise the experiment is crowned with success. In 

 a few hours a change is noticeable in the larva it has grown and 

 gained in strength. At length it pulls away from the walls of the 

 cell and settles among the spiders I have provided. It is an experi- 

 ment especially prolific in answering abstract questions and suggest- 

 ing others. It proves that all larvae are not entirely dependent on 

 one certain article of diet. Doubtless a given species is invariably 

 supplied by the parent with the same kind of food, yet we have posi- 



