50K 
Observations on Insects. 
M: Girou de Buzareingues, performed similar experiments with nearly 
the same results, upon Spinach andr Lychnis dioica. It would be impor¬ 
tant perhaps to try Hops in the same way, as results interesting to the 
hop-growers, might in all probability be thence obtained. 
J. Rennie, 
Zee, KenU 
Article XV .—Observations on the Structure of Insects^ 
and on the Transformations which they undergo. By 
Mr. John Smithurst, of Lea. 
The object of the present paper is to give a brief sketch of the struc¬ 
ture of insects in general, and also to explain the different transform¬ 
ations they undergo, before they arrive at what we may consider a 
state of perfection. The subject, I conceive to be one of great im¬ 
portance, not only to every lover of Natural History, but also to the 
Horticulturist;—I regi’et much my inability to do it justice, but I 
trust the few remarks I am about to make, will not be wholly uninter¬ 
esting to some of your readers. 
The Insect division of the animal world, received its name from the 
individuals of which it is composed, having a separation in the middle 
of their bodies, by which they are cut, as it w'ere, into two parts. 
These parts, are in general connected by a slender ligament, or hollow 
thread. Insects (with the exception of the Crab tribe) breathe through 
pores arranged along their sides; and have a scaly or bony skin, 
and many feet. Most of them are furnished with wings. They are 
destitute of nostrils and eyelids; and the mouth is in general situated 
under the head, and is furnished with transverse jaws, a kind of teeth, 
a tongue, and a palate. 
Insects have in most instances, four or six palpiy or feelers, and 
also moveable horns, which generally proceed from the front part of 
the head, and are endowed wdth a very nice sense of feeling. Some 
writers have conjectured, that the horns of insects, are their organs of 
hearing; for it is evident, from various experiments, that insects are 
possessed of this sense in as exquisite a degree as most other animals, 
although from their rninuteness, we perhaps may never discover by 
what means. The horns, however, seem little likely to answer the 
purpose of ears. These instruments of apparently exquisite sensibility, 
appear adapted to very different purposes,—but to purposes with which 
we may remain long unacquainted. 
The eyes of insects are formed of a transparent crustaceous set of 
lenses, so hard as to re(piire no coverings to protect them. These, 
