More Hunting Wasps 



family throve upon a diet now discontinued, 

 we fail to see that the descendants had any 

 reason to change it: animals have not the 

 gastronomic fancies of an epicure whom 

 satiety makes difficult to please. Because 

 the race did well upon this fare, it became 

 habitual; and instinct became differently 

 fixed from what it is to-day. If, on the 

 other hand, the original food was unsuitable, 

 the existence of the family was jeopardized; 

 and any attempt at future improvement be- 

 came impossible, because an unhappily in- 

 spired mother would leave no heirs. 



To escape falling into this twofold trap, 

 the theorists will reply that the Scoliae are 

 descended from a precursor, an indetermi- 

 nate creature, of changeable habits and 

 changing form, modifying itself in accord- 

 ance with its environment and with the re- 

 gional and climatic conditions and branching 

 out into races each of which has become a 

 species with the attributes which distinguish it 

 today. The precursor is the deus ex machina 

 of evolution. When the difficulty becomes 

 altogether too importunate, quick, a pre- 

 cursor, to fill up the gaps, quick, an imagin- 

 ary creature, the nebulous plaything of the 

 mind! This is seeking to lighten the dark- 

 ness with a still deeper obscurity; to illumine 

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