188 LARGE CABBAGE BUTTERFLY. 
service rendered to makind by these Ichneumons 
which prey upon noxious larva, from the fact, 
that out of thirty individuals of the common Cab- 
bage Caterpillar which Reaumur put into a glass 
to feed, twenty-five were fatally pierced by the 
Ichneumon. globatus, which had totally consu- 
med their intestines.* I do not, however, give this 
as an average of the numbers destroyed by their 
means. The following interesting observations by 
the Rev. Mr Bree, which are of a recent date, may 
serve to show the more probable numbers which 
suffer by this means :—‘ Towards the end of June 
last, I observed a brood of the caterpillars of Pon- 
tia brasicee, amounting in number to twenty-four, 
feeding on the cabbages in my garden. I placed 
them in confinement ; and, as they were nearly full 
grown, they soon commenced preparing for their 
transformations. By the first of July, nine out of 
the twenty-four had turned to the chrysalis state, 
and the remaining fifteen produced the silken clus- 
ters of pups of Microgaster glomoratus. I mention 
this circumstance, not at all under the idea of its 
being any thing new or extraordinary ; for I am 
aware, on the contrary, that it is one of every-day 
occurrence, and my object is to arrest the attention 
to the enormous extent to which the destruction of 
Pontia brassice is effected by the Microgaster. 
Nine caterpillars only, out of the twenty-four, 
* Reaumuwy, ii. p. 419. + 1831. 
