The Ignorance of Instinct 195 



mathematical guide beyond an irresistible im- 

 pulse that prompts her to hunt for game a 

 definite number of times. When the Sphex has 

 made the requisite number of j ourneys, when she 

 has done her utmost to store the captures that 

 result from these, her work is ended ; and she 

 closes the cell whether completely or incom- 

 pletely provisioned. Nature has endowed her 

 with only those faculties called for in ordinary 

 circumstances by the interests of her larvae ; and, 

 as these blind faculties, which cannot be modi- 

 fied by experience, are sufficient for the pre- 

 servation of the race, the insect is unable to go 

 beyond them. 



I conclude therefore as I began : instinct 

 knows everything, in the undeviating paths 

 marked out for it ; it knows nothing, outside 

 those paths. The sublime inspirations of 

 science and the astounding inconsistencies of 

 stupidity are both its portion, according as the 

 insect acts under normal or accidental conditions. 



