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Page 153,1. ir.
Furnijljid -with a margin. One of the most essential distinctions between these articulations, is, that some are placed end to end, while others inclose the extremity of the ene next them, and slip into one another, as in a groove.
Page 153,1. 15..
All caterpillars have ten. They have twelve, counting the posterior extremity, and the sirst articulation, which the author seems to take for the neck. It is not so easy to explain how M. Andri was led into the mistake, as he counts only seven articulations in the silk worm, sixteen, and even more in other caterpillars, and twelve in the ant. One would not have expected to sind such an assertion in a book written expressly on insects. If his observations on the worms which insest the human intestines, were all in the fame taste, his work would little deserve those encomiums which sill the sirst pages of his book.—See Andri de la Gener. des vers, dans le corps de I' homme.
A larva of a Tenthredo. Those which we have called pseudo-caterpillars, as I think I have already said, have properly but twelve articulations, like true caterpillars. But there are some of those pseudo-caterpillars, which have their articulations subdivided into others, and these M. Lesser seems to have counted as distinct segments.
Page 154, 1. 4.
The inseel called Hippocampus. I have shewn elsewhere, that this animal is not an insect, but a true sish.
Page 154, I. 7.
Furnijlied with a small bag. This has the appearance of a bag only on paper. Frisch gives the name of bag to the extremity of the abdomen, in the insects of the Genus, Sphex, Lin. which have that part of a different colour from the rest: and this, because the colour which distinguishes it, makes it appear, as if it were inclosed in a bag.' He gives these insects the name of sack-wespen, or wasps with a bag, to distinguish them from other wasps, It is from him that
3 D Lesser Lester gives the name of bag, to the posterior extremity of these insects.
Page 155,1. 8.
The papilla, from which they draw their threads. Spiders, which M. Lester has here in view, have eath, according to M. Reaumur, (Mem. de l'Academie de Sciences, 1713,) six. of these papillae. The extremity of a papilla, in one of the house spiders, when magnified by the microscope, appeared divided into an infinity of protuberances, smaller, but disposed much in the same way, with those that occupy the cornea in the eyes of Muscæ. Each protuberance or convexity, in this cafe, undoubtedly affords a different thread, or rather, it is probable, that each concavity, situated between those convexities, is pierced by a hole, through which the thread issues; the small elevations seem intended to prevent the threads from joining at their exit. These convexities are not so apparent, at the extremities of the papillæ, in garden spiders •, but there is observable, a quantity of small hairs, which probably serve the same purpose, that is, to separate the threads from one another. However this may be, it is certain, that of every teat in a spider, threads may be drawn from a thousand different places; so that the spider, having fix of these papillæ, has holes to allow a passage to six thousand different threads j and what is still more wonderful, these threads are already formed, when they arrive at the papillæ, and they have each its own little tract, which conducts it thither. These little tracts are, moreover, inclosed in different flesliy tubes, which Reaumur supposes to be equal in number to the papillæ; these tubes terminate in winding vessels, which he calls the great reservoirs, and of which there are three on each side of the spider; these three unite at a very long branch, which takes a serpentine course,and after having formed several turns, each terminates in a vessel which has the form of a tear of glass. These two vessels, are those which Reaumur considers as the original sources of the threads of spiders. Who could have imagined, that the formation of a spider's web required such apparatus; or, that the papillæ of so vile an animal, was an object so worthy of admiration!
Pace 155, t 16.
A fort of horns. It is said* that in some insects, as for
instance, Instance, in the aphides, these horns are the organs of respiration.
Page 156,1. 3.
*Forivards under the belly. As for instance, in the large reddish yellow spider, of which Frisch gives the history, (Aranea diadema.)—The Author.
It appears from this note that the author is speaking of a particular species of spider. That species I have not had an opportunity of observing, but I have examined several other species, and I can afsirm, that I have found the male organs placed at the head, while those of the semales were situated in the belly, precisely in the spot where Frisch plar ces those of the male in question. This would make me suspect that the spider he mentions was a semale, and the more as he represents its body as exceeding')' large, a property peculiar to the semales of spiders, for I have always found the males with an abdomen proportionally slender. Lyonet.
Page 156, 1. 5.
Situated as in the males. This is in general the case, but there are however some exceptions. The instance of the spider mentioned in the preceding note is sufsicient to shew, that there are insects whese male organs are placed difserently from those of the semale.
'Page 156, 1. 10.
Some likewise have a sting at the extremity. The author understands here by the word sting, not only that part which serves as an instrument of ofsence; but also that organ which serves as a conduit to their eggs when they introduce them into bodies which for that purpose they need to pierce. As those parts are very difserent, it would be better to distinguish them by difserent names ; that which serves them for introducing their eggs, might be called the tail, (Cauda Lin.) and the term sting (Aculeus Lin.) appropriated to that which is properly so.
Page 157,1. 3.
Often more than half an inch in length. There are ichneumons in my collection with tails near two inches long, and surpassing greatly the length of the insect itself. Ic is scl3 D 2 dom dom that the tails of Insects, which have any, terminateinr a pointed knob. The greater part of them have a cylindrical form without any sensible thickness at the extremity.
Page 157,1. 25.
* Those which deposite their eggs in other infetls. Ichneumons deposite their eggs in the bodies of caterpillars where they are hatched, and produce larvæ; these larvae maintain themselves there, and seed on the substance of the caterpillars which thereby become weak and languishing. When the larvæ have attained their size, and neither sind room nor food in the caterpillar, they make their way through its skin and then the caterpillar dies.
Page 157, I. 31.
They use it as a pike or lance. The sting is by n« means an organ peculiar to the male insects. Among bees for instance the males have no fling ; it is the fame with wasps. The semales only and the neuters are provided with it. Page icS,l. first.
Which they use as a spiracle. There are some aquatic insects which can elongate their tails to an astonishing degree. The rat-tailed larvæ are well known, not indeed so much by that name given them by Reaumur, as by the form of their tail. This organ, though longer than the animal, is only the case of another tail longer still, which is capable of great contraction, and enters into the body of the larva. This last tail is the organ of its respiration. It raises it to the surface of the water to take in air, and while itself remains at the bottom, it can send this tail to the surface tho* the water should be nearly sive inches deep; so that it can extend its tail nearly sive inches, a very considerable length for an animal only seven or eight lines long. Sec Reaumur, Tom. Iv. and Scottish Register, Vol. It.
Page 158, 1. 13.
* Larva that have their feet on the bach. This is an observation of M. de Reaumur, as may be seen in the Mem. of the Royal Academy of Sciences, i714, P. 103, and Frisch, P. 1 j. N. 7. The author.
I am not surprised that the author should advance so pofitjivcly that there is a particular class of insects both aquatic tic and terrestrial, which before their transformation have their seet on the back; but which are no sooner divested of their skin, and begin to fly, than they have their seet under the belly. Frisch in the place here quoted, expresses himself on this head in a manner so decisive, that it would appear incredulity to hesitate a moment in believing that there were such insects. These are his words when speaking of the insect we shall immediately mention. The "greatest singularity in this larva is, that it has its six legs 48 on its back. M. de Reaumur, in the Memoirs of the "Academy of Sciences, has well described a species of a"quatic larva, which his likewise its seet on the back; he "fays he is uncertain under what division of insects to claft "it. For my part, I make a particular class of these "insects, whether aquatic or terrestrial, that is, of those "insects which before their transformation, have their '* seet upon the back. To this class, belongs the insect des"cribed by Reaumur, and the beetle in question. &c." Would not one imagine from this passage that Frisch had discovered a great number of insects of this kind, and that it only remained to class them? He cites however only these two species, and I do not remember that there is another instance in his work. I do not mean to deny that there may perhaps be insects, that have at sirst their seet upon the back, and which, after their transformation, have them then under the belly ; yet I think the circumstance very unlikely, and it has never hitherto occurred to me. It appears however, that Mr Frisch has been rather precipitate in establishing a class for such. M. de Reaumur does not afsirm as a well ascertained fact, that the singular insect which he describes in the Memoirs of the Academy, has actually its seet on its back. He fays only that it has them on the back, or on the opposite side to its belly, supposing the belly to be on that side where the mouth and the anua are situated, and towards which the head generally inclines. So that if this insect had accidentally its head and the anu« placed a little differently from what is the ordinary position, in insects, a circumstance not altogether singular, it might, notwithstanding these appearances to the contrary, still have its seet on the side opposite to the back. Besides, neither Reaumur nor Frisch had seen the transformation of this animal, at least they do not mention their having seen it i and