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caterpillar of the Geometræ kind, about feven lines long, of a pale green colour, with a head compreffed and forked, and with two points at the extremity of its abdomen, which produced a well formed butterfly, having, befides the four wings common to all butterflies, between its upper and under wings, two fmaller ones, ciliated and folded double Indeed they did not feem to have been of great ufe to it in flying, but they certainly deferved the name of wings, as they had all the appearance of them. As I have never obferved more than one caterpillar of that fpeeies, I fhall not decide whether this fingularity was a lufus naturæ, or a character peculiar to that fpecies. I know however that infects afford few examples of monsters with more members than are neceffary for them, and this makes me think that the fix wings might be natural to the fpecies I mentioned. PAGE 50, 1. 13.

Sea-Stars. It would feem that Mr Leffer confiders SeaStars as animals without feet. The rays of fome of them may however well be confidered as fuch, fince there are fpecies which move them, and use them for walking; but even though this should not be the cafe, there are Sea-stars that have rays provided with a great number of feet as we have already remarked. As to thofe fpecies, they cannot be ranked among infects deftitute of feet. Befides, in the author's enumeration, he has forgot to mention fnails, flugs and many fhelled animals which would confiderably have augmented his lift.

PAGE 50, 1. 15.

The clafs of infects with two feet. See what has been faid on thefe different claffes in the preceeding Chapter.

Although Mr Leffer's Catalogue of infects be pretty confiderable, it is however far from comprehending all the infects known. He confines his clafs of butterflies to the number of 135; but Mad. Merian alone has difcovered upwards of 260, including thofe of Surinam. I have, in lefs than four years, found above 340 fpecies of butterflies, in the fpace of about a league in circuit; and I do not doubt but a little application will furnish me with many

more.

PAGE 51, 1. 4.

And fo progreffively. Mr Leffer gives us here but a vague

Idea of the multiplication of infects. As fomething more decifive, I fhall relate an experiment I made on the fubject. Although one of the most common, it will give is a more accurate idea than that in the text. The Experiment was made with the moth figured by Goedart Part 1. Exp. 59, (Phalana antiqua.) A neft of about 350 eggs, which I had from a single female of this moth, produced as many little caterpillars. As it would have been inconvenient to have fed fo many, I took only eighty, which I brought up. All of them underwent their transformations, and came to their perfect state, except five which died. Amongst all these however I had but fifteen females; whether the males are naturally lefs numerous in this fpecies, or whether it happened by chance I know not. But let us fuppofe for a moment that it always happens fo, I reason in this manner: If eighty eggs gave fifteen prolific females, the neft of 350 would have given at least 65. These 65 females, fuppofing them as fertile as their mother, would have produced in the fecond generation 22,750 caterpillars, among which there would have been at least 4265 females, which again would have given birth to 1,492,750 caterpillars for the third generation, a number greater than accor ding to Mr Leffer's calculation, the third generation of all his 765 different infects. Befides, the caterpillar I am talking of is not one of the most prolific. I know fome that produce double the number at least. And what is this in comparison with certain viviparous flies, which produce towards 20,000 young, at a fingle birth; of which confequently a fingle fly, fuppofing the number of females equal to that of the males, would produce at the third generation a pofterity of two thoufand million of millions? Let a perfon form to himfelf, if he can, an idea of the prodigious number of flies which at the end of a few years a fingle fly of this kind would produce, had not Providence taken care to limit the progrefs of fuch aftonishing fecundity. But what fhall we fay when we confider, that God created in the first of these animals, a faculty fufficient for the production of many thousand generations of their kind, which fhould continue to fucceed each other to the end of the world, and of which each individual female feems to poffels the power of multiplication in fo enormous a degree? Certainly thofe who think that all reproduction is performed by deve lopement, will here find themfelves perplexed, and will be

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obliged to acknowledge that if their fyftem is plaufible on one hand, on the other it is founded on fuppofitions which we cannot conceive to be poffible, fince for this purpose, we must be able to comprehend how the original parent fly we are peaking of, contained, in its body, fuch a prodigious number of young, that when arrived at their full growth, and united together, they would form, if I may venture to say fo, a mafs greater than would be produced by the accumulated matter of all the globes in the visible hemifphere. But this is not the only marvellous circumftance. As each young one when inclofed in the parent fly, is at least thirty thoufand times fmaller than its mother, and as we must suppose that each young one contains germs at least thirty thousand times fmaller than it is itself, and fo of the reft; here is a new fort of progreffion, ftill more marvellous than the first, by which each fly, in proportion as we confider it a step nearer to its first parent, will diminifh much more in tize than it is encreafed in number, at each generation: fo that the maggot of fuch a fly which is at prefent thirty thousand times fmaller than its mother, was three hundred million of times fmaller a generation before; and three thousand million of millions of times fmaller two generations before. Let any one judge after this of the infinite minutenefs of fuch a maggot, according to this fyftem, fome thousands of generations back. It would need, in fuppofing that flies generate only once a year, at least twenty-two thousand figures ranged confecutively, to exprefs arthimetically, how many times fmaller than a fly of its fpecies it was, when inclofed in the common mother of the fpecies. If in this fyftem of developement we fhould fuppofe that it is in the animalculæ of the male femen, that the fource of multiplication is to be fought, the wonder would greatly'encreafe: for thefe animaleule are much lefs in proportion to the males, than the fæ tufes of flies are to the female.

PAGE 51, 1. 6.

I have made no mention of maggots, caterpillars, &c. The reafon of this is plain. All the winged infects here enume rated, having been formerly maggots, caterpillars or other creeping larvæ, could not be reckoned as maggots, caterpil lars, &c. and then as winged infects without counting them twice.

NOTE

PAGE 52, 1. 7.

Food for other animals. It is not only among other animals that infects meet with enemies; thev deftroy one another. The Formica-leo (Myrmeleon formicarium) devours ants, the Hemerobius perla and a great number of larvæ feed on all forts of aphides; fpiders eat flies, and are themselves killed by wafps, and other voracious flies. The tree bugs, various larvæ which change into beetles, and many beetles and flies devour caterp Hars, pfeudo-caterpillars, maggots, butterflies, and moths; fome fpecies of caterpillars eat one another. The ichneumon flies of many fpecies destroy an infinity of larvæ by 1.ying their eggs in them which produce young, that prey on the vitals of the animal which barbours them. The carnage is ftill greater among aquatic infects; of thefe there is hardly a fpecies which is not, at fome period of its life, a prey to fome bolder or ftronger infect.

PAGE 20, 1.9.

* Locusts which lay waste the fields, have the tail too short to be able to lay their eggs deep in the earth: accordingly, birds and the injuries of the elements destroy them in great numbers; a wife ordination, of Providence, to prevent the exceffive multiplication of fo noxious an animal!

PAGE 46, 1. 6.

Every thing which lives refpires. Although this is a most general rule, it is not perhaps without exception in infects. Many have given me reafon to doubt of their refpiration, at leaft in certain ftages of their existence. I took for instance fome of thofe large cantharides of the willow, whofe ftrong fmell, though not very difagreeable, is felt at a confiderable distance. I put them under a glafs, where for a long time fulphur had been burning on a piece of copper made red hot, that the fulphur might continue to burn in the midst of its own vapours; and although there arofe fo thick a fmoke that it almoft hid my infects from fight, they supported thefe vapours for more than half an hour without fuffering, that I could perceive, the fmalleft injury.

Befides, when we confider the folidity of the greatest part of the cones made by the pfeudo-caterpillars, and the great number

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number of Ichneumon flies, we cannot conceive how, it is poffible that thefe infects fhould live feveral months under ground in a place fo clofe and fo impenetrable to the air if they needed to breathe in it. If indeed they were to breathe even the air 'which is inclofed along with them, fo fmall a portion, paffing to often through their fpiracles, and being tainted with the exhalations it could not but receive from them, would be of no use to the infect.

Neither would I maintain the refpiration of chryfalids; at least one experiment convinces me that there are some which do not always breathe. I took the chryfalis of the Sphinx Liguftri, which being one of the greateft is the most proper for experiments. It had, betides, the two anterior ftigmata fo open that with a common magnifier I could fee into the fubftance of its body and obferve a small vacuum between it and the cover. This made me hope that if refpiration took place in chryfalids, this would give me certain proofs of it. Two or three months before the perfect infect iffued from its cover, I dug it up, and covered, feveral times; first one, and then two, and afterwards fucceffively the whole of its fignata, with foap-water. At each time I obferved for a confiderable fpace, with the glafs, the ftigmata, thus covered, to fee if any bubble of air was formed above; which would naturally have happened, had thefe ftigmata ferved as conduits to the air in refpiration; but with all my attention I could perceive none. Some days afterwards, I repeated the fame experiment in a manner which appeared to me ftill more decifive. Instead of covering the ftigmata with foap-water, I covered each with a little bubble of air, taken from the froth of the fame water, that the air might enter and go out more freely. But my curiofity was not the more gratified'; thefe bubbles which ought to have rifen or funk at each expiration or infpiration of the Chryfalis preferved conftantly the fame appearance, till, their pellicle becoming dry, they burst.

When the perfect infect had iffued from this chryfalis I took it up inftantly. I washed the infide of it, and obferved at the ftigmata of its fegments little bundles composed of a great number of very white threads of which the longeft were about two lines in length. These appeared to me the exuviæ of the pulmonary organs. I blowed on each of the ftigmata with all my force, by means of a very slender tube, but my utmost efforts could neither fwell nor move

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