An Introduction to Entomology: Vol. 4

An Introduction to Entomology: Vol. 4 - or Elements of the Natural History of the Insects

Having given you this full account of the external parts of insects, and their most remarkable variations; I must next direct your attention to such discoveries as have been made with regard to their Internal Anatomy and Physiology: a subject still more fertile, if possible, than the former in wonderful manifestations of the power, wisdom and goodness of the Creator. The vital system of these little creatures, in all its great features, is perfectly analogous to that of the vertebrate animals. Sensation and perception are by the means of nerves and a common sensorium; the respiration of air is evident, being received and expelled by a particular[Pg 2] apparatus; nutrition is effected through a stomach and intestines; the analogue of the blood prepared by these organs pervades every part of the body, and from it are secreted various peculiar substances; generation takes place, and an intercourse between the sexes, by means of appropriate organs; and lastly, motion is the result of the action of muscles. Some of these functions are, however, exercised in a mode apparently so dissimilar from what obtains in the higher animals, that upon a first view we are inclined to pronounce them the effect of processes altogether peculiar. Thus, though insects respire air, they do not receive it by the mouth, but through little orifices in the sides of the body; and instead of lungs, they are furnished with a system of air-vessels, ramified ad infinitum, and penetrating to every part and organ of their frame; and though they are nourished by a fluid prepared from the food received into the stomach, this fluid, unlike the blood of vertebrate animals, is white, and the mode in which it is distributed to the different parts of the system, except in the case of the true Arachnida, in which a circulation in the ordinary way has been detected, is altogether obscure. In order that you may more clearly understand the variations that occur in insects, and in what respects they differ amongst themselves, and from the higher animals, in the vital functions and their organs, I shall consider them as to their organs of sensation, respiration, circulation, nutrition, generation, secretion, and muscular motion. ......Buy Now (To Read More)

Product details

Ebook Number: 43579
Author: Kirby, William
Release Date: Aug 27, 2013
Format: eBook
Language: English

Contributors

Contributor (Author): Spence, William, 1783-1860