230 HYMENOPTERA. 
whole genus of ichneumons, whether 
large or small. 
Lucy, Are there a great many spe- 
cies ? 
Mother, A vast number; more than 
five hundred have been enumerated and 
described. Some of these are an inch 
and a half long, while other species do 
not measure quite one eighth of an inch 
in length. 
Lucy, Can such little creatures de- 
vour others ? 
Mother, The larvas are the chief de- 
vourers. The flies are furnished with 
a sting, which is most curiously con- 
trived : it is composed of three pieces ; 
two of these form a kind of sheath, 
which contains the stiug itself. The sting 
is toothed along the edges, but in the 
middle there is a small channel, or hol- 
low groove, in which the eggs roll, and 
are thus guided to the spot where the 
fly wishes to place them. Several sorts 
of the ichneumon lay their eggs in the 
