ICHNEUMON BORERS. 27 



jointed horns, so continually on the vibrate as to have pro- 

 cured for their possessors the appellation Musicce vibrantes. 

 With these organs* (supposed to combine the uses of feelers 

 and of ears) our pryers are to be seen for ever exploring, both 

 by touch and hearing, the places and the living subjects best 

 suited to receive their eggs. 



Cuckoo-flies is another appellation by which ichneumons 

 are distinguished, because, like the cuckoo, they are accus- 

 tomed, lazily, intrusively, dishonestly, and cruelly, to deposit 

 their eggs in stranger nests sometimes within stranger egg- 

 shells sometimes within the bodies of stranger grubs and 

 caterpillars, either in their infancy or when they have attained 

 their growth. For execution of these her nefarious practices, 

 the female ichneumon is provided with a very conspicuous 

 instrument, tail-like, seeming composed sometimes of one, 

 sometimes of three divergent hairs, but consisting, in fact, of 

 a single ovipositor, or borer, with a sheath longitudinally 

 divided and opening like a pair of compasses. The nicest 

 adaptation marks this curious instrument, which, according to 

 the different species and habits of its possessor, is employed to 

 pierce, sometimes only an exposed egg, sometimes the skin 

 of a grub, caterpillar, or chrysalis, and sometimes through 

 defences strong and deep, coverings of silk, or wood, or clay ; 

 and, according to these varied requisitions, it is shorter or 

 longer, thinner or thicker, stiffer or more pliant. In one large 



* Antennae. 



