I20 The Htinting Wasps 



his observation, Darwin did not have before 

 him a Sphex in the strict sense of the word. 

 Then what did he see ? 



The term Fly, by which the captured prey 

 is designated, is a very elastic word, which can 

 be applied to the immense order of Diptera 

 and which therefore leaves us undecided among 

 thousands of species. The expression Sphex is 

 most likely also employed in an equally inde- 

 finite sense. At the end of the eighteenth 

 century, when Darwin's book appeared, this 

 expression was used to denote not only the 

 Sphegidae proper, but particularly the Crab- 

 ronidae. Now, among the latter, some, when 

 storing provisions for their larvae, hunt Diptera, 

 Flies, the prey required by the unknown 

 Hymenopteron of the English naturalist. Then 

 was Darwin's Sphex a Crabro ? No ; for these 

 Dipteron-hunters, like the hunters of any other 

 prey, want game that keeps fresh, motionless 

 but half-alive, for the fortnight or three weeks 

 required for the hatching of the eggs and the 

 complete development of the larvae. All these 

 little ogres need meat killed that day and not 

 gone bad or even a little high. This is a rule 

 to which I know of no exception. The word 

 Sphex cannot be accepted therefore, even with 

 its old meaning. 



Instead of a precise fact, really worthy of 



