32 THE SOLITARY WASPS. 



other genera), and tliat to sting a certain segment being found 

 the most successful method, this habit was inherited like the 

 tendency of a bull dog to pin the nose of a bull, or of a ferret to 

 bite the cerebellum ; and that the next step in advance was to 

 prick the ganglion only slightly, thus giving the lai-vse fresh 

 instead of dried meat.* It seems to us more probable that we 

 have in these instincts examples of the action of natural selec- 

 tion, the primary advantage of the use of the sting being to re- 

 duce the prey to helplessness. Our AmmopMla, with their 

 many-ganglioned caterpillars, have been carried some steps fur- 

 ther, and if, as may be possible, those larvae which have pro- 

 vided for them caterpillars that cannot move and that yet are 

 alive and fresh, derive any advantage from these conditions, 

 the present variable st^te of things may merge into one in which 

 the instinct will be better adjusted, approaching and perhaps 

 finally reaching that which Fabre finds in the species which he 

 has observed; but at present, speaking for A. urnaria, we may 

 say that this instinct, wonderful, complex and difficult to ex- 

 plain as it unquestionably is, is still far from being exact, either 

 in its methods or in the results obtained. 



*Life and Letters, Vol. II., p. 420. 



