Now, the manner of their production, I suppose to be thus, that the Alwise Creator has as well implanted in every creature a faculty of knowing what place is convenient for the hatching, nutrition, and preservation of their Eggs and of-springs whereby they are stimulated and directed to convenient places, which become, as ’twere the wombs that perform those offices: As he has also suited and adapted a property to those places wherby they grow and inclose those seeds, and having inclosed them, provide a convenient nourishment for them, but as soon as they have done the office of a womb, they die and wither.
The progress of inclosure I have often observ’d in leaves, which in those places where those seeds have been cast, have by degrees swell’d and inclos’d them, so perfectly round, as not to leave any perceptible passage out.
From this same cause, I suppose that Galls, Oak-apples, and several other productions of that kind, upon the branches and leaves of Trees, have their original, for if you open any of them, when almost ripe, you shall find a little Worm in them. Thus, if you open never so many dry Galls, you shall find either a hole whereby the Worm has eat its passage out, or if you find no passage, you may, by breaking or cutting the Gall, find in the middle of it a small cavity, and in it a small body, which does plainly enough yet retain a shape, to manifest it once to have been a Worm, though it dy’d by a too early separation from the Oak on which it grew, its navel-string, as ’twere, being broken off from the leaf or branch by which the Globular body that invelop’d it, received its nourishment from the Oak.
And indeed, if we consider the great care of the Creator in the dispensations of his providences for the propagation and increase of the race, not onely of all kind of Animals, but even of Vegetables, we cannot chuse but admire and adore him for his Excellencies, but we shall leave off to admire the creature, or to wonder at the strange kind of acting in several Animals, which seem to favour so much of reason; it seeming to me most manifest, that those are but actings according to their structures, and such operations as such bodies, so compos’d, must necessarily, when there are such and such circumstances concurring, perform: thus, when we find Flies swarming, about any piece of flesh that does begin a little to ferment; Butterflies about Colworts, and several other leaves, which will serve to hatch and nourish their young; Gnats, and several other Flies about the Waters, and marishy places, or any other creatures, seeking and placing their Seeds in convenient repositories, we may, if we attentively consider and examine it, find that there are circumstances sufficient, upon the supposals of the excellent contrivance of their machine, to excite and force them to act after such or such a manner; those steams that rise from these several places may, perhaps, set several parts of these little Animals at work, even as in the contrivance of killing a Fox or Wolf with a Gun, the moving of a string, is the death of the Animal; for the Beast, by moving the flesh that is laid to entrap him, pulls the string which moves the trigger, and that lets go the Cock which on the steel strikes certain sparks of fire which kindle the powder in the pann, and that presently flies into the barrel, where the powder catching fire rarifies and drives out the bullet which kills the Animal; in all which actions, there is nothing of intention or ratiocination to be ascrib’d either to the Animal or Engine, but all to the ingeniousness of the contriver.
But to return to the more immediate consideration of our Gnat: We have in it an Instance, not usual or common, of a very strange amphibious creature, that being a creature that inhabits the Air, does yet produce a creature, that for some time lives in the water as a Fish, though afterward (which is as strange) it becomes an inhabitant of the Air, like its Sire, in the form of a Fly. And this, methinks, does prompt me to propose certain conjectures, as Queries, having not yet had sufficient opportunity and leisure to answer them my self from my own Experiments or Observations.
And the first is, Whether all those things that we suppose to be bred from corruption and putrifaction, may not be rationally suppos’d to have their origination as natural as these Gnats, who, ’tis very probable, were first dropt into this Water, in the form of Eggs. Those Seeds or Eggs must certainly be very small, which so small a creature as a Gnat yields, and therefore, we need not wonder that we find not the Eggs themselves, some of the younger of them, which I have observ’d, having not exceeded a tenth part of the bulk they have afterwards come to; and next, I have observed some of those little ones which must have been generated after the Water was inclosed in the Bottle, and therefore most probably from Eggs, whereas those creatures have been suppos’d to be bred of the corruption of the Water, there being not formerly known any probable way how they should be generated.
A second is, whether these Eggs are immediately dropt into the Water by the Gnats themselves, or, mediately, are brought down by the falling rain; for it seems not very improbable, but that those small seeds of Gnats may (being, perhaps, of so light a nature, and having so great a proportion of surface to so small a bulk of body) be ejected into the Air, and so, perhaps, carried for a good while too and fro in it, till by the drops of Rain it be wash’d out of it.
A third is, whether multitudes of those other little creatures that are found to inhabit the Water for some time, do not, at certain times, take wing and fly into the Air, others dive and hide themselves in the Earth, and so contribute to the increase both of the one and the other Element.