132 



THE INDUSTRIES OF ANIMALS. 



greater, and the pursuit does not need to be so often 

 renewed; a single captive is sufficient for its larva.^ 



The sureness 

 of instinct. — 

 It is not 

 doubtful that 

 a sure inher- 

 ited instinct 

 conducts the 

 Sphex to 

 prick its vic- 

 tim in the 

 situation of 

 the nervous 

 ganglia, 

 which will be 

 wounded in 

 act. It 



f. the 



may be said 

 that the le- 

 sion results 

 from the posi- 

 tion in which 

 thehymenop- 

 terous insect 

 maintains its 

 victim ; for 

 the sting is 

 on the med- 

 ian line, and 

 can only 



^ For some remarks on the action of the Sphex, and for Darwin's 

 opinion on the matter, see Romanes' Menial Evolution in Animals, 

 pp. 299-303. 



