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For the manner in which insects have been perpetuated from their creation to this day we can easily account. Like all the other animals they multiply by means of generation. Upon receiving existence they at the same time received the power of producing their like, and of preserving in this manner, their species for ages* The fame God who created them by his power, blessed them, and ordered them to encrease, and multiply on the earth, each after its kind. Gun. t. 22.
The antient philosophers were not at all of the opinion of Moses on this point; some believing that the greater part of insects were not multiplied in theordinary way of generation, but were engendered by iill forts of matter. This they called equivocal generation, and they did not consine this idea to insects alone. Many plants according to them, could grow out of the womb of nature, without being sown of cultivated. It would not be difficult tO( shew how little solidity there is in either of :hese opinions; but as' the last does not belong to my subject, I shall consine myself solely to demonstrate the falsity of the sirst.
Observers of nature having remarked swarms of insects in different substances, imagined that those diminutive animals, were produced immediately, without the concourse of any animal of their own species.' Such they found in putrid flesh, in the entrails of animals, in the leaves of plants, in rivers, in rain water, in snow and in dust; therefore said they, it is from these substances that they derive their existence. If these philosophers were asktd how such a thing could happen; they gravely answered, that the heat of the Sun, augmenting the sermentation of these substances, the insects were produced by the sermentation. People'were long satissied with such reasoning, because no one ever took the trouble of examining
ing the subject more closely. The moderns, better observers than the antients, at last arrived at the truth. They found that insects only grow in such substances, when others of the fame species have previously deposited their ova in them; and that the Sun has no further effect in their generation, than that of giving the necessary warmth to these ova. The experiments of Redi alone, an accurate naturallist leave no room to doubt of the fact; they are decisive.
To assure himself that insects are not produced from corruption, he took the flesh of Serpents, of Pigeons, Oxen, Horses, and Fishes; and put these into two crystal vessels, one of which was shut, and the other open. "What was the consequence? A short, time afterwards, the open vessel swarmed with little maggots, that turned afterwards to flies; while the other did not produce a single insect. But it may be said there would have been no difference in the two vessels, had not the air been intercepted, and consequently the production of the insects prevented. This objection occurred to our naturalist and engaged him to institute a new experiment. He filled a fhird vessel with a similar mixture, and covered the aperture with gauze, sufficiently tight to exclude all insects, but open enough to allow a free entrance to the air. Undoubtedly the fame insects would have been found in this vessel 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 vessel which was covered with gauze did not contain any animals.
The opinion that Insects are generated from plants is not better founded. On this subject we have the decision of the celebrated Malpighi, whose authority will appear respectable to all who know the merits
I of that learned Physician. It is known that mag*
gots and flies, breed in protuberances on trees called Gall-nuts. These insects would appear at sirst evidently produced by what is called equivocal generation; and so the vulgar believe; but Malpighi discovered that flies deposited their eggs on those trees, that they were the occasion of those tumours, and that from the ova grew maggots which at last produced flies like the parent,
But there is no necessity for adducing more proofs of a fact in favour of which common sense speaks so decidedly. How can we conceive that a substance should produce another of a nature much more excellent than its own? But this would be the case of a plant which should produce insects. If it were true that it could give us such 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, so as to render it sit for the production of an insect; which surpasses its power. The semen of an animal does not arrive at that degree of perfection necessary for the production of another animal, without the assistance of a great number ot faculties, of which plants are entirely destitute. What elaborate preparation in the proper vessels! what digestion, what secretion, what circulation, before that matter is sufficiently purisied, and has acquired its necessary qualities! Insects which lay eggs have the vessels necessary for their formation; they are endowed with the faculties necessary for their fecundation, and the' means of discharging them when they arrive at maturity. Nothing of all this is to be found in Plants. Whatever analogy there may be, in many circumstances, between them and animals a very great difference is observable between their functions, their faculties, thew-vascular
«•«- system system, their means of propagation; it can never therefore appear credible that they have the power of generating Insects, the production of which requires so many qualities of which they are destitute. I maintain the fame thing of all other inanimate bodies; and I do not hesitate to say that a Watch, with all its wheels, might sooner grow from the filings of steel, than an Insect could be formed by an inanimate body, however perfect the organs of that body might be in its kind.
Intelligent persons never give into an opinion so ill sounded as that 1 am refuting. They easily perceive that it is contrary to reason, and to the course of nature; they even find weapons to combat it in the sacred Scriptures. Indeed, we may remark that God gave to every creature, the loss ot which would have drawn with it that of the whole sptcies, the 'faculty of producing its like, before it mould perifil itself. He diJ not leave this office to chance, but willed that every species should contain in itself the germ and seed of an animal, or of a plant of the same species, 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, whose seed is in itself upon the earth." These plants therefore have their feed in themselves and can perpetuate their own species, but they can produce nothing tlse. It is not otherwise 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 solely to its own species, and it would be vain to suppose, thar an insect could produce insects of a species different from its own. Gen. i. ai. 22. 28. Since that time no derangement has taueri place, no interruption in the order which God at
E first sirst established. Vegetables have continued to preserve and multiply themselves by their seed, and insects by their eggs. Can we doubt then that God included insects in the number of those animals to which he gave his benediction after he had created them? The command to encreasc, to multiply and replenish the earth, wns given to them no less than to the other species 01* living creatures. And if it was given to them, must they not be subject to the same laws, and perpetuate themselves in the fame manner?
If we attend to the foregoing reasoning we shall be easily persuaded that insects possess all the parts necessary for generation; that there is among them different sexes; that they pair, and that they enjoy all the necessary organs for the formation and preservation of their ova. To these I add another observation, which is, that if Insects were ingendered in the manner contended for by those antient Philosophers, we should every day see new species. The action of the Sun on plants and putrid substances is not so uniform but it would often vary its products, and it would therefore be astonishing if we did not every day see legions of unknown Insects.
But let not these reflections on the origin of insects be regarded with contempt. It is of more importance than at sirst sight it seems, to be acquainted with the source of multiplication is these little animals. After we are once convinced that they produce themselves by natural means, inseparable from their species, we can declare war against the ancients, we can combat their adherents, and resute those ideas which they have promulgated at the expence of the glory of the Creator. If insects arose from putrefaction, sermented by the heat of the Sun, the same thing might be the case with other Animals and even with mankind.