CHAPTER IX 

 ANTS, BEES, WASPS, AND THEIR KINDRED 



WHICH order of insects is the " highest "i.e., 

 the most advanced in point of evolutionary 

 progress ? The question may seem superfluous, in 

 view of the facts that many different lines of develop- 

 ment are apparent, and that each type of insect is well 

 fitted for the life which it leads. Yet some insects are 

 manifestly more specialized than others. The details 

 of their structure and metamorphosis evince such pro- 

 found modification, such delicate adjustment to ex- 

 ternal conditions, that further improvement seems 

 hardly possible. Judged by this standard of physical 

 perfection, the more advanced families of the Diptera 

 stand supreme ; but for the highest refinement of the 

 mental faculties we must turn to ants, bees, and wasps. 

 These insects are included in the order Hymenoptera, 

 which must now engage our attention. 



The majority of Hymenopterous insects have four 

 membranous wings, which are never very large, and 

 of which the nervures are never very numerous. 

 Except in a few minute species, the wings of each side 

 are united during flight by a row of hooks on the 

 front margin of the hind-wing, which engage with a 

 fold on the hind margin of the fore-wing. These 

 hooks cannot be seen without the aid of a fairly power- 

 ful lens, but their presence may be demonstrated by 



106 



