For the manner in which infects have been perpe tuated from their creation to this day we can easily account. Like all the other animals they multiply by means of generation. Upon receiving exif tence they at the fame time received the power of producing their like, and of preferving in this manner, their species for ages. The fame God who created them by his power, bleffed them, and ordered them to encrease, and multiply on the earth, each after its kind. GEN. 1. 22.

The antient philofophers were not at all of the opinion of Mofes on this point; fome believing that the greater part of infects were not multiplied in the ordinary way of generation, but were engendered by all forts of matter. This they called equivocal generation, and they did not confine this idea to infects alone. Many plants according to them, could grow out of the womb of nature, without being fown or cultivated. It would not be difficult to fhew how little folidity there is in either of thefe opinions; but as the last does not belong to my fubject, I fhall confine myself folely to demonftrate the falfity of the firft.

Obfervers of nature having remarked fwarms of infects in different fubftances, imagined that thofe diminutive animals, were produced immediately, with out the concourse of any animal of their own fpecies. Such they found in putrid fleth, in the entrails of animals, in the leaves of plants, in rivers, in rain water, in fnow and in duft; therefore faid they, it is from thefe fubftances that they derive their existence. If thefe philofophers were afked how fuch a thing could happen; they gravely answered, that the heat of the Sun, augmenting the fermentation of these fubftances, the infects were produced by the fermentation. People were long fatisfied with fuch reafoning, becaufe no one ever took the trouble of examin

ing the fubject more clofely. The moderns, better obfervers than the antients, at laft arrived at the truth. They found that infects only grow in fuch substances, when others of the fame fpecies have previously deposited their ova in them; and that the Sun has no further effect in their generation, than that of giving the neceffary warmth to thefe ova. The experiments of Redi alone, an accurate naturallift leave no room to doubt of the fact; they are decifive.

To affure himfelf that infects are not produced from corruption, he took the flesh of Serpents, of Pigeons, Oxen, Horfes, and Fishes; and put these. into two crystal veffels, one of which was fhut, and the other open. What was the confequence? A fhort time afterwards, the open veffel swarmed with little maggots, that turned afterwards to flies; while the other did not produce a fingle infect. But it may be faid there would have been no difference in the two veffels, had not the air been intercepted, and confequently the production of the infects prevented. This objection occurred to our naturalist and enga ged him to inftitute a new experiment. He filled a third veffel with a fimilar mixture, and covered the aperture with gauze, fufficiently tight to exclude all infects, but open enough to allow a free entrance to the air. Undoubtedly the fame infects would have been found in this veffel which were observed in that which had been open to the air, if corruption alone could have made them grow. But that did not hapen. The veffel which was covered with gauze did not contain any animals,

The opinion that Infects are generated from plants is not better founded. On this fubject we have the decifion of the celebrated Malpighi, whofe authority will appear refpectable to all who know the merits

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of that learned Phyfician. It is known that maggots and flies, breed in protuberances on trees called Gall-nuts. Thefe infects would appear at first evidently produced by what is called equivocal generation; and fo the vulgar believe; but Malpighi difcovered that flies depofited their eggs on thofe trees, that they were the occafion of thofe tumours, and that from the ova grew maggots which at last produced flies like the parent,

But there is no neceffity for adducing more proofs of a fact in favour of which common fenfe speaks fo decidedly. How can we conceive that a fubftance fhould produce another of a nature much more excellent than its own? But this would be the cafe of a plant which fhould produce infects. If it were true that it could give us fuch productions, it could not give them, but in one of two ways, either by means of an unapt material, which would approach very nearly to a creation; or by purifying that material, fo as to render it fit for the production of an infect; which furpaffes its power. The femen of an animal does not arrive at that degree of perfection neceffary for the production of another animal, without the affiftance of a great number of faculties, of which plants are entirely deftitute. What elaborate preparation in the proper veffels! what digeftion, what fecretion, what circulation, before that matter is fufficiently purified, and has acquired its neceffary qualities! Infects which lay eggs have the veffeis neceffary for their formation; they are endowed with the faculties neceffary for their fecundation, and the means of difcharging them when they arrive at maturity. Nothing of all this is to be found in Plants. Whatever analogy there may be, in many circumftances, between them and animals a very great difference is obfervable between their functions, their faculties, there vasculaṛ

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fyftem, their means of propagation; it can never therefore appear credible that they have the power of generating Infects, the production of which requires fo many qualities of which they are deftitute. I maintain the fame thing of all other inanimate bodies; and I do not hesitate to fay that a watch, with all its wheels, might fooner grow from the filings of fteel, than an Infect could be formed by an inanimate body, however perfect the organs of that body might be in its kind..

Intelligent perfons never give into an opinion fo ill founded as that I am refuting. They eafily perceive that it is contrary to reason, and to the courfe of nature; they even find weapons to combat it in the facred Scriptures. Indeed, we may remark that God gave to every creature, the lofs of which would have drawn with it that of the whole fpecies, the faculty of producing its like, before it fhould perish itfelf. He did not leave this office to chance, but willed that every fpecies fhould contain in itfelf the germ and feed of an animal, or of a plant of the fame fpecies, and not of any other. "Let the "earth, fays the Creator bring forth grafs, the herb "yielding feed, and the fruit tree, yielding fruit after "his kind, whofe feed is in itfelt upon the earth." These plants therefore have their feed in themtelves and can perpetuate their own fpecies, but they can produce nothing elfe. It is not otherwife with animals. After God had created them, each after its kind, he gave them the faculty of multiplying by generation. Each after its kind had thenceforth the power of producing its like; but this power was confined folely to its own fpecies, and it would be vain to fuppofe, that an infect could produce iniects of a fpecies different from its own. Gen. 1. 21. 22. Since that time no derangement has taken place, no interruption in the order which God at

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firft eftablished. Vegetables have continued to pre ferve and multiply themselves by their feed, and infects by their eggs. Can we doubt then that God included infects in the number of thofe animals to which he gave his benediction after he had created them? The command to encrease, to multiply and replenish the earth, was given to them no lefs than to the other fpecies of living creatures. And if it was given to them, muft they not be subject to the fame laws, and perpetuate themfelves in the fame manner?

If we attend to the foregoing reafoning we shall be easily perfuaded that infects pofsefs all the parts neceffary for generation; that there is among them different fexes; that they pair, and that they enjoy all the neceffary organs for the formation and prefer vation of their ova. To thefe I add another obfervation, which is, that if Infects were ingendered in the manner contended for by thofe antient Philofophers, we fhould every day fee new fpecies. The action of the Sun on plants and putrid fubftances is not fo uniform but it would often vary its products, and it would therefore be aftonifhing if we did not every day fee legions of unknown Infects.

But let not these reflections on the origin of infects be regarded with contempt. It is of more importance than at first fight it feems, to be acquainted with the fource of multiplication is thefe little animals. After we are once convinced that they produce themselves by natural means, infeparable from their fpecies, we can declare war against the ancients, we can combat their adherents, and refute thofe ideas which they have promulgated at the expence of the glory of the Creator. If infects arofe from putrefaction, fermented by the heat of the Sun, the fame thing might be the cafe with other Animals and even with mankind.

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