56 The Htmting Wasps 



met with no accident whatever. If we repeat 

 the experiment on the same specimen, twice, 

 thrice, or four times over, the results remain the 

 same, until the wound becomes too serious and 

 the insect actually dies, as is proved by its 

 desiccation and putrefaction, which follows soon 

 after. 



The Melasoma-beetles and Longicornes are 

 more sensitive to the action of the ammonia. 

 The injection of the corrosive drop pretty 

 quickly renders them motionless ; and, after 

 a few convulsions, the insect seems dead. But 

 this paralysis, which would have persisted in the 

 Dung-beetles, the Weevils and the Buprestes, 

 is only temporary here : within a day, motion is 

 once more apparent, as energetic as ever. It 

 is only when the dose of ammonia is of a certain 

 strength that the movements fail to reappear ; 

 but then the insect is dead, quite dead, for it 

 soon begins to decay. It is impossible, therefore, 

 to produce complete and persistent paralysis 

 in Beetles that have their ganglia far apart by 

 the same measures which proved so efficacious 

 in Beetles with ganglia close together : the 

 utmost that we can obtain is a temporary 

 paralysis whose effects pass off within a day. 



The demonstration is conclusive ; the Cer- 

 ceres that prey on Beetles conform in their 

 selection to what could be taught only by the 



