i/2 OUR INSECT FRIENDS AND FOES 



backward, and transporting sand grains to build 

 them with with minute care, as if doing a useful 

 work. The orifice being thoroughly blocked, 

 she brushed herself, seemed to give a glance of 

 satisfaction at her work, and finally flew off." 



Now, as the Sphex had gone down and 

 inspected the violated cell, she must have seen 

 that it was empty, and yet she acted exactly 

 in the same way as she would have done had 

 the egg and the provisions been safely within. 

 The experiments tend to prove that the insect's 

 actions are purely automatic and instinctive, one 

 act following another with the regularity of 

 clockwork. First, the Sphex makes her burrow ; 

 secondly, she provisions it ; thirdly, she lays an 

 egg; and lastly, she closes the burrow. The 

 first, second, and third acts having been per- 

 formed the Sphex is impelled to continue with 

 the fourth and last act of closing her burrow, 

 even when it is an utterly useless and futile 

 proceeding. 



On one occasion, however, M. Fabre chanced 

 upon a colony of S. flavipennis in which a few 

 solitary individuals acted as though they did 

 possess a certain degree of reasoning power, 

 by taking their prey straight down into the 

 burrow without leaving it on the threshold, after 

 it had been removed several times. 



When the Sphex has furnished a cell with 

 sufficient provisions, generally three or four 

 crickets piled one on the top of another, she lays 

 an egg. This is not deposited anywhere in a 

 haphazard fashion, but is invariably placed on 

 one particular spotthe cricket's breast, not 



