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female a creeping infect with fix feet, which has scarcely any refemblance to it. It is likewife one of the most general rules, that all proper caterpillars become butterflies or moths and yet among them we find many fpecies where the male alone turns into a perfect infect of that kind, the female changing into a dull ill-fhaped animal without wings. The rule is that all maggots fubject to a change are metamorphofed either into flies or beetles; and yet the flea, though it fprings from a maggot, is neither the one nor the other. The ant likewife comes from a maggot, and yet few of them become winged. All thefe fingularities are fo many difficulties which occur in the plan I have sketched, as they do in many inftances in the fyftems of Swammerdam, Linnaeus and Leffer; but as difficulties of this kind will always be unavoidable in every fyftem which attempts a natural order, because the rules of that order however general they may be, are seldom univerfal; there is no other way but that of endeavouring to reconcile fuch difficulties with the plan devised. This may be done by affigning to infects of a doubtful clafs, that class in which the individuals are found, which are the most perfect of their fpecies; and to infects which belong properly to no divifion, that to which they have the nearest relation. Thus the winged aphides which from this circumftance are the most perfect of their fpecies, belong to the fecond general clafs in our system. According to my divifion, I would have no difficulty in' comprehending every fpecies of aphis in this fecond class, For the fame reason, the female glow worm would be found among the beetles with their males, and the unwinged lepidopteræ, fhould be ranged in the fame clafs with the males; the winged ants would bring the whole fpecies to the clafs of flies, and the relation which the flea has in many respects with beetles, would make it take its ftation at the end of the animals of that order. In this manner might difficulties be obviated, and a methodical arrangement facilitated.

PAGE 43, 1. left.

The Gordius. This is an aquatic worm. There are fome terrestrial animals, which deferve as well as this to be called thread-worms. Caterpillars nourish fome of them in their inteftines. I have feen fome iffue of different lengths from more than one fpecies of caterpillars that feed on the alder. A caterpillar of the length of an inɔh, furnished me with

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one ten inches long, and which was not nearly fo thick as the first ftring of a violin. This worm fo much resembled a piece of cat-gut, that if one did not fee it move, one could hardly believe it was an animal.

PAGE 44, 1. 2.

The Water Tipula. This must be fome particular species for in general the water Tipulæ have feet: and what is uncommon, and what no one has as yet obferved, I know fome of them which may be faid to be a kind of quadruped. They have two kinds of legs or crutches at the anterior part of their body, and two at the hinder part. Thefe legs, which is another fingularity, are stiff and without joints. The anterior ones, a third fingularity, instead of being provided each with a pointed nail, are armed with a circle of hooks, and both feet are moved at once, but with a motion always parallel and uniform from top to bottom, and vice verfa. I know not whether the pofterior ones be moveable ; I have always found them stiff like fticks. If the four limbs I have juft mentioned, can be called true feet, this infect will make an exception to the rule I laid down in the preceeding Chapter, to wit, that no creeping infect is a quadruped.

PAGE 44, 1. 7.

Hippocampus. As the fulcra of this little animal form a perfect skeleton, it ought rather to be confidered as a fifh than as an infect.

PAGE 44, 1. 21.

Even the inteftines of animals. Of all animals, none perhaps are so liable to nourish worms in their inteftines as infects. The ichneumons, which are of many different fpecies, derive their origin for the most part from larvæ which have fed on other infects and deftroyed them.

PAGE 44, 1. 31.

I know a fpecies of water flea. It is far from being certain that there are any infects with only two feet. None fuch are found among thofe that live on land. God feem's to have distinguished by this character men and birds from the rest of terreftrial animals. It is not even very certain that there are bipeds among the aquatic infects. Those that

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pafs for fuch are the pulices aquatici, mentioned by the au thor, and the larva of the (Afilus) but if we examine accurately what are fuppofed to be the feet of both thefe animals, we will find that, as to the Pulex aquaticus, they are rather a fort of oars, which the animal ufes in its progreffive motion, than true feet: for far from having the form of feet, they are two trunks placed' near the head. They divide each of them into two branches whence other fmaller branches iffue which circumflances do not agree with the idea we have of feet, nor indeed are they fit for performing the functions of feet. But even though thefe oars fhould pafs for true feet, the fame pulices feem to have others under the belly, which from their minuteness feem to have efcaped the obfervation of Leffer, and which prevent thefe animals from being confidered as bipeds. As to the larva of the Afilus, what would have been its feet are two fhort articulated members, two forts of beards which iffue from the fides of its mouth. Their fituation and - minutenefs ought rather to make them pafs for beards than for feet, although Swammerdam affirms that they are cafes for the extremities of the feet of the future fly. Moreover this animal when arrived at its perfect state, has fix legs, and accordingly it cannot with propriety be claffed with bipeds. But if infects have not hitherto furnished us with certain examples of animals with two feet, one would perhaps be furprised to hear that they furnifh us frequently with examples of thofe that have but one. However frange this may appear, we do not hesitate, with M. Reaumur, to mention a great number of Bivalve thelled animals poffeffing a muscular organ which they extend a great way beyond their fhells. This organ is their foot, and they use it in tranfporting themfelves from place to place.

PAGE 45, 1. 3.

The Formicaleo, It is no doubt from the refemblance in the name, that the Formicaleo is placed among the Formica or ants, thefe infects refembling each other in nothing else. The first in form rather looks like a spider; it devours ants and is therefore called formicaleo.

* Linnæus calls it Myrmeleon Formicarium.

PAGE 45, 1. 20.

Land and water Scorpions. The flat and winged Cimex commonly

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commonly named the water fcorpion has only fix feet. The land ones, at leaft fuch of the fpecies as are known to me, have ten feet, counting the two large fore feet which are armed with claws or pincers.

PAGE 45, 1. 24.

The caterpillars called geometra. These caterpillars have generally ten feet. The fpecies that have twelve are very rare. I know but three forts. None have been found, fo far as I know, which have eight feet, though a first rate naturalift fuppofes there may be fuch.

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The common caterpillars. Thefe have fixteen feet, comprehending the two hinder ones; but the author, it would feem does not count them, I know not for what reafon, fince he reckons the hinder ones of the geometræ among their feet. It is even the more neceffary that these should be reckoned in the common caterpillars because there is a fort of caterpillars with fourteen feet, that have no hind ones. Thefe, with regard to the number of their feet, would be confounded with the common caterpillars if the posterior feet of fuch as have them were not to be counted. Befides, the caterpillars which want the hind feet, there are alfo fome other fpecies which do not want them, and yet have only fourteen feet. These, and the former are the only ones that can be ranked in the clafs which the author here speaks of.

PAGE 45, 1. 27.

We obferve eighteen feet. There is no true caterpillar known which has eighteen feet. Thofe which have more than fixteen and which resemble caterpillars are as M. de Reaumur names them pfeudo-caterpillars, that is, fuch as though pretty similar to caterpillars are not really fo, as they naturally change into flies with four wings (Ichneumons or Tenthredos) while the true caterpillars change into butterflies or moths. If there be any pfeudo-caterpillars with eighteen feet, they must be very rare, for I have never found any. All thofe I have feen had twenty or twentytwo feet, and indeed that which Leffer here fpeaks of, on the authority of Mad. Merian has really twenty by her account. But I fufpect very much that he has been deceived

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as fhe fays that it produced a phalena. This would be an unexampled cafe, and two fingular to be credited on the au thority of a perfon more intent on painting infects than in describing them exactly. There is every reafon to believe that she had miftaken the chryfalis of a true caterpillar for that of the pfeudo-caterpillar in queftion; and I imagine that she made a fimilar mistake in Part II. No 3. of her European infects, where the fays, that a butterfly came from a caterpillar with twenty-four feet.

PAGE 45, 1. 32.

Beetle with a probofcis. This likewife would be a fingular fact in Natural History if it were true, I do not believe that any naturalift has ever feen a larva with four and twenty-feet producing a beetle, nor indeed does Mad. Merian, whom M. Leffer quotes here as his authority, fay that the animal in queftion had four and twenty feet. It is in the defcription of the third and not of the fecond plate of her fecond part that the fpeaks of an ochre-coloured larva found in rotten wood, which changes into a beetle. Some lines above she had spoken of a caterpillar with twenty-four feet. These two defcriptions are printed clofe together in my Edition, and occupy only ten lines. The author has probably read the first four lines, where the fpeaks of the four and twenty feet of her pretended caterpillar, and then skipping two or three lines has read what the fays of the larva of the beetle. Without further confideration, he must have taken the pfeudo caterpillar and this larva for one and the fame ani mal; and has given to the larva the feet of the pfeudo-caterpillar without this explanation, it is impoffible to comprehend how he could quote the authority of Mad. Merian for beftowing four and twenty feet on a larva not mentioned by her

PAGE 46, 1. 2.

One hundred and eighty four feet. This number of feet cannot but appear very confiderable to those who reflect on the multitude of fprings, which must enter into the internal conftruction of fo fmall an animal, in order to put fo many machines in motion. But after this with what afto nishment will we not be ftruck at the fight of an animal which has fifteen hundred and twenty feet, as one species of fea ftars has. What do I fay? even two thousand one hun

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