WASPS, SOCIAL AND SOLITARY 



were not the handy workman of to-day. 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 se- 

 verely 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 egg or larva is so firmly fastened 

 as to keep its hold, while in the latter the dead and de- 

 composing caterpillar is eaten without dissatisfaction or 

 injury. 



Nor do we, in gathering evidence for the evolution of 

 the instincts of these wasps, need to rely entirely up6n 

 our own observations. 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, needing 

 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- 



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