The Red Ants 



are the manoeuvres of which I can avail myself 

 to gauge the elasticity of the Wasp's memory. 

 While the Pompilus is at work upon the 

 burrow, I seize the prey and place it in an ex- 

 posed spot, half a yard away from its original 

 position. The Pompilus soon leaves the hole 

 to enquire after her booty and goes straight 

 to the spot where she left it. This sureness 

 of direction, this faithful memory for places 

 can be explained by repeated previous visits. 

 I know nothing of what has happened before- 

 hand. Let us take no notice of this first ex- 

 pedition; the others will be more conclusive. 

 For the moment, the Pompilus, without the 

 least hesitation, finds the tuft of grass whereon 

 her prey was lying. Then come marches and 

 counter-marches upon that tuft, minute ex- 

 plorations and frequent returns to the exact 

 spot where the Spider was deposited. At last, 

 convinced that the prize is no longer there, the 

 W^asp makes a leisurely survey of the neigh- 

 bourhood, feeling the ground with her 

 antennae as she goes. The Spider is descried 

 in the exposed spot where I had pl^ed her. 

 Surprise on the part of the Pompilus, who 

 goes forward and then suddenly steps back 

 with a start : 



153 



