194 THE SOLITARY WASPS. 



end of the limb. Two stings were given at eack of wMcli the 

 crayfish straightened out violently. After a few seconds the 

 legs relaxed and their tips began to quiver just as we have seen 

 them do in spiders found in mud-nests. In a moment the cray- 

 fish became perfectly limp and remained lying either on the 

 dorsal or the ventral side, as it was placed. From eleven in the 

 morning until two in the afternoon, when it died, the maxi- 

 lipedes and ambulatory legs kept moving irregularly. The 

 sting could scarcely have reached a ganglion, so that the death 

 of the crayfish was due to the diffusion of the poison. This ex- 

 periment we repeated several times, substituting Pelopaeus 

 cementarius in place of Polistes fusca, and always with the 

 same results. 



We next took a large spider, E. slrix, and breaking off the 

 second leg at the femur let the^ wasp sting it at the point of frac- 

 ture. This was at nine o'clock in the morning and the spider 

 remained limp and unable to move until five in the afternoon 

 when it partly recovered and began to move about with diffi- 

 culty. On the following day it still moved about slowly but 

 was far from appearing normal, and on the morning of the 

 third day it was dead. On the eighth day it was still plump 

 and in good condition although the sixth and seventh days had 

 been very hot, 90° Fahr. 



On July fifteenth we let Polistes fusca sting a spider, E. 

 labyrinthea, in the middle of the upper surface of the abdo- 

 men. The spider remained in a motionless state with the legs 

 drawn up, until the next day, when it died. On July twenty- 

 fourth the spider was shrunken but the legs were still flexible 

 and the body soft. 



We next let P. cementarius sting Marptusa fainiliaris^ 

 twice at the spinnerets. The spider was paralyzed at once, all 

 the legs being limp although they quivered at the tips, but in 

 five minutes it recovered somewhat and was able to stagger 

 about. This continued for ten minutes when the wasp was al- 

 lowed to sting it again in the same place with the same imme- 

 diate result as before but this time there was no recovery and in 



