Chapter IX 



THE SPIDER-HUNTERS 



WHILE Ammophila provides caterpillars for her 

 larva, and Bembex, after the manner of the 

 social wasps, feeds her young from day to day on dead 

 flies, the Pompilidae, so far as their habits are known, 

 all prey upon spiders. The family is a large one in the 

 United States, one hundred and twenty-seven species 

 having been described. The members of the group differ 

 in size, color, and habits, and the individuals of the same 

 species show the very considerable amount of variation 

 which seems common to all those groups of animals 

 which have been carefully studied. Happily the old 

 notion that habits and instincts, unlike structural pe- 

 culiarities, are always uniform, is no longer insisted 

 upon, and there is ample evidence for the opinion that 

 functional variations are as common as morphological. 

 We have studied five species of this family, and have 

 found their respective r61es of great interest. 

 According to Fabre, the French members of this 

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