178 INSECT LIFE xn 



These facts seem to demonstrate that if S. 

 flavipennis can compute exactly how many victims 

 to catch, she cannot attain to counting how many 

 reach their destination, as if the creature had no 

 other guide as to number than an irresistible im- 

 pulse leading her to seek game a fixed number of 

 times. When this number of journeys has been 

 made, — when the Sphex has done all that is possible 

 to store the captured prey, — her work is done, and the 

 cell is closed, whether completely provisioned or not. 

 Nature has endowed her with only those faculties 

 called for under ordinary circumstances by the in- 

 terests of the larva, and these blind faculties, 

 unmodified by experience, being sufficient for the 

 preservation of the race, the animal cannot go farther. 



I end then as I began : instinct knows every- 

 thing in the unchanging paths laid out for it ; 

 beyond them it is entirely ignorant. The sublime 

 inspirations of science, the astonishing inconsis- 

 tencies of stupidity, are both its portion, according 

 as the creature acts under normal conditions or 

 under accidental ones. 



