2 Mr. J. O. Westwood on a Species 
when full fed, have the instinct to eat a hole, about a quarter of an 
inch in diameter, through the hard shell of the fruit, whilst it re- 
mains upon the tree ; through this hole they then creep to the 
stem of the fruit, and spin a white web, which they attach to the 
basal part of the fruit as well as to the stem, for about the distance 
of an inch along the latter. This web is sufficiently strong to sup- 
port the pomegranate from falling after the wind has broken the 
stem near to the fruit ; as is the case in the specimen of the fruit 
exhibited, and as represented in my figure. 
From the circumstance of this specimen having as many holes in 
it as there were caterpillars inhabiting it, it is most probable that 
the web thus spun is a joint production of the whole.* 
But it will be at once asked, what necessity could there be for 
the caterpillars to secure the fruit from falling after each has bored 
a hole, and thus made its escape? This question is answered by 
the curious circumstance that, after so securing the fruit, the cater- 
pillars return again into the pomegranate, in the hollow interior of 
which they undergo their transformation to the chrysalis state. 
Here, too, we may notice another interesting fact ; namely, that 
the insect has the precautionary instinct, which acts as a second 
inducement, to make the aperture in the fruit in that stage of its 
existence in which it is furnished with organs best adapted for the 
purpose ; for, had the larva omitted taking this step, the consequence 
would have been, that the poor insect, when come to its butterfly 
state, would have been a prisoner totally unable to make its escape, 
being unprovided with any instrument sufficiently powerful to make 
a hole in the shell. Some Lepidoptera, we know, such as the puss 
moth, are able, on arriving at the perfect state, to make their way 
out of cocoons, which are even harder than the shell of the pome- 
granate ; but in these instances the cocoon has been rendered hard 
by means of glutinous matter secreted by the caterpillar, which the 
newly hatched moth has power to dissolve. 
Many Cofeoptera, especially amongst the wood-feeding species, 
have the instinct, immediately before assuming the pupa state, to 
eat a passage almost to the surface of the substances within which 
they reside, leaving only a thin covering, which the newly-hatched 
imago is able without difficulty to eat through.'}' But in this butter- 
* It is curious, as evidencing the instinctive impulses under which each of the 
inclosed larva? must have acted, that, instead of availing themselves of the first 
aperture made in the fruit, each caterpillar should be at the trouble of making a 
hole for itself, a circumstance which rendeis it the more probable that all joined in 
spinning the web. 
t In some instances, however, even amongst the Coleoptera, a perfect orifice is 
