fore of believing and being grieved by the belief, that the insect we tread upon

"In corporal sufferance finds a pang as great

As when a giant dies,"

the very converse is nearer the truth. "Had a giant lost an arm or a leg," continue the authors just quoted, "or were a sword or spear run through his body, he would feel no great inclination for running about, dancing, or eating. Yet a tipula (crane-fly) will leave half its legs in the hands of an unlucky boy who has endeavoured to catch it, and will fly with as much agility and unconcern as if nothing had happened to it; and an insect impaled on a pin will often devour its prey with as much avidity as when at liberty. Were a giant eviscerated, his body divided in the middle, or his head cut off, it would be all over with him; he would move no more; he would be dead to the calls of hunger, or the emotions of fear, anger or love. Not so our insects: I have seen the common cockchaffer walk about with apparent indifference after some bird had nearly emptied its body of its viscera; a humble-bee will eat honey with greediness though deprived of its abdomen; and I myself lately saw an ant, which had been brought out of the nest by its comrades, walk when deprived of its head. The head of a wasp will attempt to bite after it is separated from the rest of the body; and the abdomen, under similar circumstances, if the finger be moved to it, will attempt to sting."

Why do insects live, and (so far as we can perceive,) feel comparatively little pain from the loss of their limbs ?

Because, though possessed of nerves, they have nothing similar to our brain and spinal cord, the two sources of our nerves of feeling and of motion; but, instead of this, they have a chain of ganglia, or bundles of nervous substance, and from each of these bundles, nerves branch out to the parts contiguous,

each ganglion forming the centre of feeling to the parts to which its nerves run, or having its own set of

nerves.

Many curious particulars connected with the great tenacity of life in insects are mentioned by entomologists, as well with a view to illustrate the animal economy, as to defend their favourite pursuit. Riboud stuck different beetles through with pins, and cut and lacerated others in the severest manner, without greatly accelerating death. Leuwenhoeck had a mite which lived eleven weeks transfixed on a point for microscopical observation. Vaillant caught a locust at the Cape of Good Hope, and after excavating the intestines, he filled the abdomen with cotton, and stuck a steel pin through the thorax, yet the feet and antennæ were in full play after the lapse of five months. A decapitated beetle will advance over a table, and recognise a precipice on approaching the edge. Colonel Pringle decapitated several libellulæ, or dragon-flies, one of which afterwards lived for four months, and another for six; and, which seems rather odd, he could never keep alive those with their heads on above a few days. Mr. Haworth, the well-known English entomologist, being in a garden with a friend who firmly believed in the delicate susceptibility of insects, he struck down a large dragon-fly, and in doing so he unfortunately severed its long abdomen from the rest of its body. The mutilated insect after this devoured two small flies. Mr. Haworth then contrived to form a false abdomen, by means of a slender portion of a geranium; after which the dragon-fly devoured another fly, and, on being set at liberty, it flew away with as much apparent glee as if it had received no injury. It is well known to practical entomologists, that large moths found asleep during the daytime, may be pinned to the trunks of trees without their appearing to suffer such a degree of pain as even to awake them. It is only on the approach of the evening twilight that they

seek to free themselves from what they must no doubt regard as an inconvenient situation.*

Considerations such as those glanced at in the preceding page can never, of course, be so misconstrued as to afford any palliation to wanton or inconsiderate cruelty to the brute creation.

Why does the skin of insects differ from that of the vertebral animals?

Because, in insects, the skin serves the double purpose of protection and support, and represents the cutaneous and osseous system of the latter. Its structure appears much more simple than in the higher classes, as it can neither be said to possess a mucous or cellular web or true skin. It bears the nearest resemblance to the cuticle of the skin of the higher classes, or, rather, all the lamina of perfect skins are here incorporated into one uniform plate. In some genera it is soft and pliable; while, in others, as some of the weevils, it approaches the consistence of bones, or appears as a calcareous crust in the crabs. In some species it is elastic, in others brittle.(Fleming.) Again, the coat, composed of several portions, moving on one another like the pieces of a gauntlet, also serves to protect the insect from the effects of various accidents.

Why are not the spines and hairs of insects easily rubbed off?

Because they are merely elongations of the skin. It is otherwise with scales. Some of these are inserted into the skin at one end and left free at the other, and in some insects are so feebly connected, as to fall off by touching them with the finger. These scales, in the butterfly, bear a remote resemblance to feathers in their form.

Why do many insects leap, with ease, forwards, backwards, and laterally?

* See Encyclop. Brit., art. Animal Kingdom, vol. iii. 7th edit. 1831.

Because the thighs of their hind legs are of uncommon size, to give room to the requisite number of muscles. Why do insects fly?

Because the muscles which move their wings take their rise in the breast, and are capable of executing their functions with great celerity.

The flying insects do not possess rapidity of flight proportional to the number and size of their wings. In the coleoptera, the body hangs down during flight, while in other classes it preserves nearly a horizontal position.

The wings are composed of two membranes, an upper one, in which nervures or cords are traced; a lower one, separable from the upper. These nervures or cords contain a spiral vessel, "whence they appear," says Kirby, "to be air vessels communicating with the trachea in the trunk. The expansion of the wing at the will of the insect is a problem that can only be solved, by supposing that a subtle fluid is introduced into these vessels, which seems perfectly analogous to those in the wings of birds; and that thus an impulse is communicated to every part of the organ, sufficient to keep it in proper tension: we see by this, that a wing is supported in its flight like a sail by its cordage." Why are the wings of insects important to the naturalist?

Because they, in a great measure, furnish the characters employed in classification. Thus, the presence or absence of wings their number and appendices -their texture and consistence, together with their size, position, and manner of folding up, yield marks which are easy of detection, and which experience has found to be perfect.-Fleming.

Why are the upper wings of insects called elytra or wing-cases?

Because they serve as a covering to the inferior

ones. Strictly speaking, these elytra are not wings, since they perform no other motion than elevation and depression, and serve merely to protect the wings when at rest, not to assist them when flying.

Why are not aquatic insects wet with the water in which they reside?

Because the skin is probably smeared with some unctuous matter; comparative anatomy hitherto having failed in detecting any glands subservient to the functions of the skin. In some instances, indeed, the skin resists being wet, even after the death of the animal has taken place for some time, but previous to becoming dry.-Fleming.

Dr. Arnott physically attributes it to the weight of the insects not being sufficient to overcome the cohesion of the particles of water among themselves.

In the tribes which swim, the legs are either flattened like the blade of an oar, or produced and ciliated (fringed) on the edges. Some swim upon their back, others upon their belly. Some keep always floating upon the surface, others dive and perform their movements at various depths, regulated by the condition of the organs of respiration.-Fleming.

Why were insects and worms formerly called bloodless animals?

Because they are distinguished from the preceding classes by the absence of red blood, in place of which they have a white fluid. In recent times, on account of the absence of vertebræ and ribs, they have received the name of Invertebral Animals.

Among the crustaceous animals, as the lobster and shrimp, the blood is white; while, among some insects, as the grasshopper, and white caterpillar, it is green.-Hewson, Phil. Trans.

Why are insects supposed to possess a heart?

Because, both in their perfect and larvæ state, they have a membranous tube running along the back, in