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being, from a dew that in the spring falls upon the leaves of trees; and that some kinds of them are from a dew left

upon herbs or flowers; and others, from a dew left upon coleworts or cabbages : all which kinds of dews being thickened and condensed, are by the sun's generative heat, most of them, hatched, and in three days made living creatures:' and these of several shapes and colours; some being hard and tough, some smooth and are horned in their head, some in their tail, some have soft; some none; some have hair, some none: some have sixteen feet, some less, and some have none: but (as our Topsel hath with great diligence

In his History observed) those which have none, move upon

of Serpents. the earth, or upon broad leaves, their motion being not unlike to the waves of the sea. Some of them he also observes to be bred of the eggs of other caterpillars, and that those in their time turn to be butterflies; and again, that their eggs turn the following year to be caterpillars. And some affirm, that every plant has its particular fly or caterpillar, which it breeds and feeds. I have seen, and may therefore affirm it, a green caterpillar, or worm, as big as a small peascod, which had fourteen legs; eight on the belly, four under the neck, and two near the tail. It was found on a hedge of privet; and was taken thence, and put into a large box, and a little branch or two of privet put to it, on which I saw it feed as sharply as a dog knaws a bone: it lived thus, five or six days, and thrived, and changed the colour two or three

(1) The doctrine of spontaneous or equivocal generation is now universally exploded; and all the phænomena that seem to support it are accounted for on other principles. See Derham's Phys. Theol. Chap. 15, and the authorities there cited. As also Mr. Ray's Wisdom of God manifested in the works of the Creation, 298, and Franc. Redi, De Gen. Insect.

(2) Whoever is desirous of knowing more of Caterpillars, and of the several flies produced by them, may consult Joannes Goedartius De Insectis, with the Appendix of Dr. Lister, Lond. 8vo. 1685.

times, but by some neglect in the keeper of it, it then died, and did not turn to a fly: but if it had lived, it had doubtless turned to one of those flies that some call Flies of prey, which those that walk by the rivers may, in Summer, see fasten on smaller flies, and, I think, make them their food. And 'tis observable, that as there be these Flies of Prey, which be very large; so there be others, very little, created, I think, only to feed them, and breed out of I know not what; whose life, they say, nature intended not to exceed an hour;' and yet that life is thus made shorter by other flies, or by accident.

(1) That there are creatures “ whose lise nature intended not to exceed an hour,” is, I believe, not so well agreed, as that there are some whose existence is determined in five or six. It is well known that the Ephemeron, that wonderful instance of the care and providence of God, lives but from six in the evening till about eleven at night; during which time it performs all the animal functions; for, in the beginning of its life, it sheds its coat; and that being done, and the poor little animal thereby rendered light and agile, it spends the rest of its short time in frisking over the waters : the female drops her eggs, which are impregnated by the male; these, being spread about, descend to the bottom by their own gravity, and are hatched by the warmth of the sun into little worms, which make themselves cases in the clay, and feed on the same without any need of parental care. Vide Ephem. Vita, translated by Dr. Tysson, from Swammerdam. See also Derham's Phys. Theol. 247.

And to the truth of the assertion, that these short-lived animals shed their coats, I myself am a witness; for, being a fishing one summer evening, at about seven o'clock, I suddenly observed my cloaths covered with a number of very small fies, of a whitish colour inclining to blue; they continued fixed while I observed those on my left arm wriggle their bodies about, till at length they disengaged themselves from their external coat, whịch they left, and flew away; but what greatly astonished me was, that three whisks which each of these creatures had at its tail, which were slepderer than the finest hair, aod, but for their whiteness, would have been scarcely perceptible, were left as entire and unbroken as the less tender parts of the coat.

At the time when I was preparing for the press the first edition of this book, I met (in a book entitled The Art of singling improved in all its parts, especially Fly-fishing, 12mo. Worcester, no date, by Richard Bowlker) with a relation similar to this; which the author says was communicated to him by a gentleman, an accurate observer of nature's productions; and giving credit to the assertion, I inserted it as an extract from his book; but I liave since dis'covered that the same had been communicated to the Royal Society by Mr. Peter Collinson, a London tradesman, well known among botanists and collectors of natural curiosities, in a Letter to their secretary, which was read the 21st of January, 1744-5, and is printed in the Philosophical Transactions for the year 1746, Numb. 481, page 329.

The letter is miserably written; and, in respect of the style, so ungrammatical, and otherwise obscure, as to need such interpolations as are here inserted, to render it in any degree intelligible.

'Tis endless to tell you what the curious searchers into nature's productions have observed of these worms and flies: but yet I shall tell you what Aldrovandus, our

The author, walking by the side of the river at Winchester, May 26, 1944, was shewn the May-iy, [conjectured to be the musca tripilis mentioned in Moufet, Insect. Theatr. p. 61. and is questionless the grey drake,] which (he says) lies all the year, but [except] a few days, in the bottom or sides of the river, (we must suppose in its nymphatic state, like the cadis, straw-worm, and other species of the libella ;] and rising, when mature, to the surface of the water, splits its case, and appears an animal ; [a fly he must mean ;) having a slender body, and three long hairs at the tail, and four blackish veined traps., parent shining wings, the under much the smaller, and the upper having four black spots.


says, that having disengaged itself from its exuvia, [i.e. the case above mentioned,] of which, he adds, he saw innumerable floating on the water, the next business of this creature is flying about to find a proper place to fix on, as trees, rushes, &c.; and that having fixed, it waits for another change, which in two or three days is completed, and which he thus describes :

The first hint I received of this wooderful operation, [i. e. the second trans. formation,]. I took froin the appearance of their exuviæ [he must here mean their second exuvia hereafter mentioned] hanging on the hedges. Of these, (not the exuvia, but the fies] I collected many; and putting them into boxes, could easily discover when they were ready to put off their old cloaths, though so lately put on."

He says, he had the pleasure to shew his friends one of these creatures, that he held on his finger all the while it performed this great work; and that it was surprising to see the back part of the fly split open, and produce a new birth, [i.e. a new fly,] which left the case of the head, body, wings, legs, and even the three-haired tail (of the old one,] behind it. He adds, that after it had reposed itself awhile, it flew abroad with great briskness, to seek a mate.

After an enumeration of some particulars which I choose to omit, he says, he observed that when the females were impregnated, they left the males, and be.. took themselves to the river ; where darting up and down, they were seen to eject a cluster of eggs, which seemed a pale bluish speck, like a small drop of milk, as they (the specks) were sinking to the botlom of the river; and that, then, (when the flies had thus ejected their eggs,] by the elasticity of their tails they sprung up, and darted down again, continuing so to do till, having ex. hausted their stock of eggs, together with their strength, they were able to rise do more, and became an easy prey to the fish. This is the end of the females ;' but of the males he says, that they never resort to the waters, but, after they have done their office, drop down, languish, and die, among the trees and bushes.

The conclusion of his letter, for I am tired of abridging it, I give in the author's own words, “They appear at six o'clock in the evening. On the 26th of May 1 perceived a few; but the 27th, 28th, 29th, and 30th, it was a sight very surprising and entertaining, to see the rivers teeming with ippumerable pretty nimble flying animals, and almost every thing near covered with them : when I looked up, the air was full of them as high as I could discern, and seemed so thick, and always in motion; (the air he tells you, but he means the flies ;) the like it seems when one looks up and sees the snow coming down. And yet this wonderful appearance, in three or four days after the last of May, totally disappeared."

(1) Ulysses Aldrovandus, a great physician and naturalist of Bologna; he wrote 120 books on several subjects, and a treatise De Piscibus, published at Franckfort, 1640.

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