AMMOPHILA AND HER CATERPILLARS. 31 



-events. And all tliis variability we get from a study of nine 

 wasps and fifteen caterpillars! 



In his chapter on "Methode des Ammophiles" Fabre says that 

 •each species has its own tactics, allowing no novitiate. "Not 

 one could have left descendants if it were not the handy work- 

 man of today. Any little slip is impracticable when the future 

 of the race depends upon it." And yet we find that the prey 

 may be stung so slightly that it can rear and wriggle violently 

 or so severely that it dies almost at once, and in neither case is 

 a break made in the generations of the Ammophiles, since in 

 the former, the e>g^ or larva is so firmly fastened as to keep its 

 liold, while in the latter the dead and decomposing caterpillar is 

 eaten without dissatisfaction or injury. 



l^ov do we, in gathering evidence for the evolution of the in- 

 stincts of these wasps, need to rely entirely upon our own obser- 

 vations. Fabre himself gives many facts which point in the 

 •same direction, but he draws a line between those actions which 

 are the result of mechanical and unvarying instinct and those 

 which come within the sphere of reason, and in relation to which 

 the insect must consider, compare, and judge. Yet this line, 

 even in the light of his own work, is so extremely variable, need- 

 ing readjustment with every new species and often among the 

 individuals of the same species, that it loses for others the 

 meaning which it has for its author. He himself speaks of 

 ■certain individuals of the genus Sphex which refuse to be duped 

 when he withdraws their prey to a distance. These, he says, 

 ■are the elite, the strong-headed ones, which are able to recog- 

 nize the malice of the action and govern themselves accordingly, 

 hut these revolutionists, apt at progress, he goes on to say, are 

 few in numbers. The others, the conservators of old usages and 

 'Customs are the majority, the crowd. Yes, but is it not always 

 the strong-minded few that direct the destiny of a race? 



Darwin's suggestion in relation to the stinging instincts of the 

 ^solitary wasps is that they originally killed their prey by sting- 

 ing them in many places on the lower and softer side of the body 

 (this habit of killing outright is still seen in Bemhex and many 



