WASPS, SOCIAL AND SOLITARY 



how he fed a specimen of Polistes carnifex with a cater- 

 pillar, which the wasp cut into two parts, goes on to say: 

 "Being at the time amidst a thick mass of fine-leaved 

 climbing plant, it proceeded, before flying away, to take 

 note of the place where it was leaving the other half. To 

 do this, it hovered in front of it for a few seconds, then 

 took small circles in front of it, then larger ones around 

 the whole plant. I thought it had gone, but it returned 

 again, and had another look at the opening in the dense 

 foliage down which the other half of the caterpillar lay." * 

 He then remarks that when the wasp came back for the 

 remaining half it flew straight to its nest without taking 

 any further note of the locality. Both of these writers 

 believe that many of the actions of insects that are 

 ascribed to instinct are really evidence of the possession 

 of a certain amount of intelligence. 



To return to our Sphex. When she flew away we nat- 

 urally supposed that she had gone in search of her prey, 

 and we were on the qui mve to observe every step in her 

 actions when she came home. Alas ! when she came back 

 half an hour later, she was empty-handed. She dug for 

 four minutes, then flew off and was gone two minutes, 

 then returned and worked for thirty-five minutes. An- 

 other two minutes' excursion, and then she settled down 



1 Naturalist in Nicaragua, p. 136. 

 60 



