34 BEES AND WASPS [OH. 



Natural Selection it is impossible, to imagine that all 

 these singular contrivances are mere purposeless 

 accidents playing no part in the general economy of 

 the species. The fact that they are confined to the 

 male renders it certain that they are not concerned 

 with procuring food or storing larders for the benefit 

 of the offspring, and makes it not improbable that 

 they are secondary sexual characters which perform 

 some useful function, perhaps in the act of mating; 

 but of their exact use we are absolutely ignorant. It 

 is to be hoped that perhaps some few of those into 

 whose hands this volume may come will be stimulated 

 by this frank confession of ignorance to make a patient 

 study of these interesting insects, and eventually 

 discover what part is played by these singular ex- 

 crescences to which we have now called attention. It 

 would not be difficult to draw up a list of almost 

 equal extent dealing with curious modifications in 

 the shape of the antennae, or at least of portions of 

 them ; and here again we should be compelled to 

 admit total ignorance. But to ascertain the uses of 

 the several modifications in this case would necessitate 

 expert knowledge and training in the methods and 

 technique of microscopy. 



In their general habits these Sphegids are not 

 unlike the other Fossors, for the females stock the 

 burrows in which they deposit their eggs with two- 

 winged flies and other insects. As might be expected 



