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in the discourse he made at the Areopagus, likes wise places respiration among the best gifts of the Deity : “ he giveth to all life, and breath and all things." ACT8 xvii. 25. An action fo necessary, and which is at the same time common to all aniinals, requires that I should stop a nioment to consider it, and endeavour to display all the skill and the wisdom of him who is its author. ,
Some antient philosphers, fuppofing that infects had neither wind-pipe nor lungs, have denied their respiration ; but the air pump, invented by Otto Get rickin , and various experiments have convinced the moderns of the contrary. If we put an insect under the receiver of that instrument and then pump out the air, it first grows weak and then dies. It is not therefore to be doubted but that insects like other animals have both wind-pipe and lungs. The first gives a free passage to the air and the last like a bel. lows inhale it when they dilate, and expell it when they contract. If we stop the wind-pipe of animals they can no longer breathe and they die : the fame thing happens to insects when their respiration is obstructed. All insects have not the wind-pipe in the same place of the body. In some it is found at the mouth, others in the extremity of their body toward the tail, in which they differ from all other animals.
All sorts of air are not proper for respiration ; it must be temperate; air either too thick or too thin would destroy life; the one makes animals die in a very short time, and a too long abode in the other does not fail to produce the same effect. But however necessary air may be for life, fome there are which can dispense with it for four and twenty hours. If at the end of this period air is restored to them
they recover their strength and do not appear to have been incommoded.
· But what deserves our particular attention is, that these minute creatures, though air is so necessary to them in summer, live during the winter with very little respiration if any at all. They are then in a sort of deep or lethargy, in a state between life and death. The salt and the viscid humour which tran. fpire from their bodies grow hard by the cold, and form a species of crust around them. In this state the pores of their bodies are contracted and in a manner shut: the vital spirits are concentrated in the interior parts of the insect, and they lose nothing of them by transpiration. As they make no motion, nothing is dissipated : they remain always in the same state, and have no occasion to respire in order to acquire new strength.
. We cannot sufficiently admire the goodness of the Creator in providing for the wants of his creatures: If air is neceffary for their existence, he gives it to them. The quality and quantity of this cannot be the same for all animals ; he gives to each the organs necessary for inhaling just what is sufficient for them, and the kind that suits them. He weighs and def. tributes it to them as it were by measure. Men en. joy this precious gift in the same way with insects; but how few are there who have given themselves the trouble of reflecting on a benefit without which it would be impoflible to live. How have they requited Him for it? From our birth we have breathed, the air is common to all animals, and they enjoy it with: out labour or expence ; and therefore instead of be. ing grateful, men become insensible to so precious a gitt. As each inspiration and each expiration are so many authentic teftimonies of the power, of the wisdom and the goodness of God, there is not a
. moment of our lives which does not invite us to celebrate his perfections and to express our own gratitude. The Palmist was penetrated with the justice of this reflection. " Let every thing that hat breath “ says he, praise the Lord.” PSALM CL. 6.
CH A P. VI.
OF THE GENERATION OF 'INSECTS,
WHEN a living creature produces another of the fame species with itself, we say that it has engendered it. All generation is preceded by an intercourse between the male and the female. This is a general rule from which infects are not excepted ; the only difference to be remarked with regard to them is, that the way in which the male insects couple with the females is different in different species. However, this commerce fecundates the female and puts her in a condition to lay her eggs when the season has arrived. The Ephemera is singular in this point ; for it is only after the female has deposited her eggs on the fura face of the water that the male fecundaies them.
The variety among the eggs of insects is incredible: it may be said to equal the number of species. Without considering the difference in their fize, I fhall only remark the most striking diversities among them whether from their figure or colours. The most common figures are the round, ihe oval, and the conic; but it must be attended to that there are some more and some less fo, and that some approach more to these figures than others. As to colours the dif
ference ference is more striking. Some like thofe of fome spiders have the fplendor of little pearls ; others like those of Nie silk-worm are yellow and of the ci lour of a grain of millet. Others are of the colour of sulphur, of gold, or of wood. Lastly there are some green and brown, and among these last there are various tinges of brown, such as yellowish brown, reddish brown, chesnur, &c.
The matter which these eggs contain is at first a liquid fubftance, and afterwards forms the infect, which is very artfully enclosed in the shell. There it remains till the superabundant humidity is diffipated, and its members liave acquired strength enough to break the egs, when it comes out. At this period it makes a hole in the shell raises up the little broken pieces, Itretches forward thehead, which hitherto had been bent in towards the belly; displays its antennæ, and puts them in motion ; brings out its legs one pair atter another, attaching itself with the first pair to the egg, till the whole body is drawn out.
All insects do not remain equally long in the egg. A few hours is sufficient for some, while it requires many days, and even many months before others break their prison. Eggs, which during winter have been in a warm place, foon lose their humidity and are hatched prematurely. It is worthy of remark, and must not be forgotten, that those caterpillars which live on green vegetables, never leave their eggs till the herbs and leaves they feed on are sufficiently advanced.' Providence has been careful to provide for their necessities, and to insure them of food the moment they want it.
Another circum?ance not less remarkable, is that many of these eggs, notwithstanding their minuteness and delicacy are able to resist both cold and wet which do not destroy them. But even though num.
bers of them should be destroyed, that loss would be easily repaired by the fertility of the females. One infect generally lays a great number of eggs ; from thirty to fixty and even some hundreds. This I learnt by the following circumstance.' On the 6th of June 1.736, a forester brought me a butterfly, the upper wings of which were dark, Ipotted with eight white fpois, and the under wings orange coloured. I fixed it with a pin to a board, and on the afternoon of the same day, found that it had laid four hundred and thirty one eggs of the size of a grain of millet, which resembled small pearls. At first they were soft, as I easily perceived because they were ilat on that fide which rested on the board, and resembled the top of a loaf. Their figure cannot be observed while they lie one upon another; they must be detached to have a distinct view of them. In ten minutes they became so hard that when they were pierced with a pin they cracked like the shell of a pullet's egg. The liquor that issued from them was whitish like water. When put into the microscope, they appeared femi-transparent like a hog's bladder. The next day the same butterfly had laid 170 eggs making in all fix hundred and one.
The observation I have just made to shew the fertility of insects will likewise prove that eggs are foft when discharged by the female; this I was convinced of likewise by another experiment. I took a butterfly of another species which I fixed to a board like the other. As soon as it had laid an egg I touched it with the point of a pin, and found that I could make little pits in it; nearly as in a blad. der which is not quite blown. Some ; nutes afterwards these eggs became hard, and when I pressed them strongly, they broke in several places like the eggs of a pullet. II 2