MASON-WASPS. 



27 



Mandibhs—Jaivs of Mason-Wasp.— Greatly magnified. 



a piece usually about the bigness of a mustard-seed. 

 It might have been supposed that these fragments 

 would have been tossed out of the hole as the 

 work proceeded, without further concern ; as the 

 mole tosses above ground the earth which has been 

 cleared out of its subterranean gallery. The wasp 

 was of a different opinion ; for it was possible that 

 a heap of brick chips, at the bottom of the wall, 

 might lead to the discovery of her nest by some of 

 her enemies; particularly by one or other of the 

 numerous tribe of what are called ichneumon flies. 

 This name is given to them, from the similarity of 

 their habit of destroying eggs to that of the little 

 animal which proves so formidable an enemy to the 

 multiplication of the crocodile of Egypt. They may 

 be also denominated cuckoo flies, because, like that 

 bird, they thrust their egg into the nest of another 

 species. These flies are continually prowling about 

 and prying into every corner, to find, by stealth, a 

 nidus for their eggs. It might have been some such 

 consideration as this which induced the wasp to carry 

 oflTthe fragments as they were successively detached. 

 That concealment was the motive, indeed, was proved ; 

 for one of the fragments which fell out of the hole by 



