beautifully constructed saw (hence the common name), for the purpose of depositing its eggs therein. The mother Saw Fly, having selected a branch adapted to her object, alights upon it, and commences to cut a groove in it with her saw, which is situated near the anal extremity of her body, and is well fitted for its office, being furnished with two rows of teeth capable of separate and continued action, so that when one row of teeth is protruded forwards, the other is drawn backwards, thus giving the insect all the advantage of two saws. This instrument is not only a saw, but is also a rasp; for each of its teeth, upon examination, is found to be furnished with several sharp and parallel ridges: in which respect it possesses a superiority over the saws used by our mechanics. Many inventions in daily use among us, we know, were originally suggested by the structure of animals ;* but it strikes me as somewhat strange that no one has hitherto made a saw upon this principle. We further find that this instrument is not merely a saw and a rasp, but is likewise an ovipositor, having a hollow channel passing through it from the base to the apex. When the groove in the branch is ready for the reception of the egg, the saw ceases its operation, and next performs its extra duty of ovipositor by depositing, in proper order, the eggs as they issue from the oviduct. So soon as an egg is laid, the ovipositor is retracted a little, but speedily again protruded; and a small quantity of liquid matter, of a frothy appearance, is then observed to fall upon the egg, and is probably intended to gum it to its bed. After the eggs are deposited in the groove, the cut in the branch is not conspicuous at first, but it at length assumes a blackish colour, and becomes raised. "This increased elevation' is said, by the author of Insect Architecture, who appears formerly to have devoted considerable time and attention to the study of insects, not to be owing to the growth of the bark, the fibres of which, indeed, have been destroyed by the ovipositor saw, but to the actual growth of the egg; for when a new-laid egg of the Saw Fly is compared with one which has been several days enclosed in the groove, the latter will be found to be very considerably the larger.' He also states that, as the egg 'continues to increase, it raises the bark more and more, and consequently widens,

* We think some philosophers are much too fond of determining the habitudes and inventions of man, to be derived from the lower animals; as if the lords of the creation were not in possession of innate faculties to render him competent to achieve anything original! Some have actually gone so far as to state that the idea of vocal and other music had its origin in the singing of birds!-EDS.

at the same time, the slit at the entrance, so that when the grub is hatched, it finds a passage ready for its exit. The mother fly seems to be aware of this growth of her eggs, for she takes care to deposit them at such distances as may prevent their disturbing one another by their development.'" The circumstance of the eggs growing as here stated is singular, yet not peculiar to this family, for the eggs of some other insects increase in size after being laid; but it affords, I may remark, a slight connection between insects and plants, as of some of the latter the seeds, which are equivalent to the eggs of oviparous animals, visibly expand previous to germination. Such is a sketch of the general habits of the Tenthredinidæ; but it must not be accepted as applicable, in all its particulars, to the species under notice, whose history I am sorry I cannot minutely detail, though I do not suspect that, if it were fully described, it would present us with ought remarkably different from this. Should the eggs of the Trichiosoma lucorum be discovered to increase in size, as do those of the majority of Tenthredinidæ (and which I have no reason to doubt they do), then the insect becomes doubly interesting, by its furnishing us with a similar fact to that observed in the seeds of plants, and consequently forming a minor point of union between the animal and vegetable creation; while, in the circumstance of its antennæ resembling those of the Papilionidæ, or butterfly family, a connection is formed between the orders Hymenoptera and Lepidoptera. The flight of Trichiosoma lucorum probably resembles that of most of its congeneric species in being low and short; a circumstance that invalidates the opinion of those who assert, merely because they see Saw Flies suddenly appear in great abundance, that they come from the sea. I have but once seen this insect alive in its perfect state, and then it seemed to be of a very sluggish nature: I have seen the larvæ three or four times. My friend, Mr. R. Ogilvie, and myself, when in company on a Natural History ramble, had once the pleasure of witnessing a very remarkable circumstance in the larva of this insect, which, upon being touched, spirted out of the pores of its body a thin, watery fluid, in fountain-like jets, of some height, comparing them to the size of the animal. This fact I have recorded in the Magazine of Natural History (vol. vi., p. 157); but, in consequence of having been misled by a figure in Shaw's Zoology, I have attributed the fact unintentionally to the larva of Tenthredo Amerinæ, a much rarer species. In the above journal I have expressed my opinion that the object of its ejecting a liquid upon being disturbed, might have been to repel our liberties, or to induce us to abandon our capture, as the

ejection of fluids is a natural plan of defence resorted to by several animals of different classes: as, for example, by the Llama, Skunk, &c., among the mammalia; the Petrel and Vulture among birds ; the Sepia among fishes; the Catchweed Beetle, (Timarcha tenebricosa), the Oil Beetle (Proscarabæus vulgaris), the larvæ of Cerura vinula, &c., among insects.*

Of the hard cocoons of Trichiosoma lucorum, I have seen several specimens; and they are, as Mr. Curtis observes, pretty common round London, on the branches of hedges. In what manner these are formed, does not appear to have been discovered; but, from examination, I am led to conceive that the ligneous materials (for of such they seem to be constituted) are first masticated into a paste, which is then spread into the required shape, its tenacity and durability being, perhaps, obtained by the aid of a glutinous secretion. When the insect has escaped from its cocoon, this exhibits the appearance of a deep cup furnished with a round lid, the hinge of which is so elastic, that the two parts are pressed so closely together, as to render the line of their division not at first very observable."+

"The larvæ of this insect (Trichiosoma lucorum) having been peculiarly abundant this season, on all the Hawthorns around Dundee, I have had," says Mr. William Gardiner, “an opportunity of observing their habits, and can corroborate the curious fact of their ejecting from the pores of their bodies, a liquid, in thin fountain-like coluinns, as stated by Mr. Fennell in the Mag. Nat. Hist., vi., p. 157. The doubt expressed in this

Work, vol. vii., 266, of this habit being usual to the species, has probably arisen from the circumstance of its being manifested only during the earlier stages of the insect's existence; for, when the larvæ appears in its last coat, no trace of this habit remains. The fluid, which is of a green colour, and strong disagreeable odour, is spirted with such violence, as often to force it to the distance of more than a foot from the insect; and its use is, perhaps, to defend the larva, in its more tender state, from the annoyance of the Ichneumon flies. In the last stage of its growth, the head, which, in the previous stages, was black, is of a bright red colour, gradually softening into yellow towards the sides; and the body appears less mealy-like, but is thickly covered with white transverse ridges. They feed only during the night, and repose themselves, half coiled up, on the under sides of the leaves throughout the day. They first made their appearance here, this season, about the 22nd of June (1834), and in the beginning of August, were transformed into pupa."-Mag. Nat. Hist., viii, p. 628.

"I have found," says Mr. Gardiner, "the beautiful figure and description (of the cocoon), with which Mr. Woodward has furnished us in Mag. Nat. Hist. v., 85, perfectly accurate, with the exception of his supposing it possible that the fibrous appearance of it was owing, in part, to the aglutinated hairs of the larva.' The larva, unfortunately, cannot apply its hairs

FOOD OF THE LARVE OF EPHEMERE.-Mr. Rennie says that the larva of the May Fly (Ephemera) "feeds, if we may judge from its egesta, upon the slime or moistened clay with which its hole [in the banks of rivers, &c.] is lined." I have often kept numbers of the larvæ of Ephemera, and observed that when any of them died they soon disappeared: I believe the survivors used them as food.

SLEEP OF ANIMALS, p. 261.—“ All observers agree that Ants labour in the night, and a French naturalist is, therefore, of opinion that they never sleep; a circumstance which is well ascertained with respect to other animals, such as the Shark, which will track a ship in full sail for weeks together." The Golden Carp (Cyprinus auratus), according to Dr. Hancock, is never observed to sleep.See Quarterly Journal of Science, No. 16, p. 291.

WHITE ANTS (Termites), p. 287.-At the Entomological Society's meeting, on February 1, 1836, was exhibited a specimen of the nest of the White Ants, Termites, being the first brought to this country. It was of small size, though some are as high as ten or twelve feet. Several spherical case fuzes, destroyed by the Wood Ant of Barbadoes, were also exhibited, from the United Service Museum, to which collection they had been forwarded by Lieut. Col. Biron. At a previous meeting, on Jan. 6, 1834, was exhibited a piece of wood greatly perforated by Termites in the East Indies; and Capt. Smee observed that, from observations he had made in India, it appeared to him that Termites were much more destructive, in consequence of a powerful acid which they leave upon every thing they pass over, than from their merely feeding upon such substances.

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EFFECTS OF CERTAIN ELECTRIC STATES OF THE WEATHER UPON ANIMALS, p. 344.-" Frogs, Cats, and other animals," says M. D'Isjonval, "are affected by natural electricity, and feel the change of weather; but no other animal more than myself and my spiders." During wet and windy weather he accordingly found that they spun very short lines, "but when a Spider spins a long thread, there is a certainty of fine weather for at least ten or twelve days afterwards." See an article on the effects of electricity, &c., upon animals, published in the Field Naturalist's Magazine, ii., 91.

INSECTS SPINNING EGG-BAGS, p. 354.—It is well known that most Spiders spin a sort of bag to inclose their eggs, but the only

to such a purpose, for the best of all reasons, because it does not possess any; so that it is likely that Mr. Woodward, when he hazarded this conjecture, had not seen the insect in its larva state."-Mag. Nat. Hist., viii., p. 628.

insects (Spiders are not of this class) known to spin one for theirs are the Hydrophili, a species of Water Beetles.-See Introduction to Entomology, iii., 72.

CLEANLINESS OF SPIDERS AND INSECTS.-"On coming down the Maine," says Mr. Rennie, "by the steam-boat from Frankfort, in Aug., 1829, we observed the geometric net of a conic Spider (Epeira conica) on the frame-work of the deck, and as it was covered with flakes of soot from the smoke of the engine, we were surprised to see a Spider at work on it; for, in order to be useful, this sort of net must be clean. Upon observing it a little closely, however, we perceived that she was not constructing a net, but dressing up an old one; though not, we must think, to save trouble, so much as an expenditure of material. Some of the lines she dexterously stripped of the flakes of soot adhering to them; but in the greater number, finding that she could not get them sufficiently clean, she broke them quite off, bundled them up, and tossed them over. We counted five of these packets of rubbish which she thus threw away, though there must have been many more, as it was some time before we discovered the manœuvre, the packets being so small as not to be readily perceived, except when placed between the eye and the light. When she had cleared off all the sooted lines, she began to replace them in the usual way."

In the Entomological Magazine, iii., p. 337, a writer states that he has often observed Flies, when covered with pollen, busy themselves in scraping it off, and then roll it up into a pellet with the fore-legs, and throw it away with a sort of jerk.

GALLS PRODUCED BY INSECTS, p. 370.-At the Breslau meeting of the German Naturalists, Sept. 1833, Dr. Hammerschmidt made some observations on the galls produced on plants by insects, with an attempt at their classification, illustrated by figures of not less than 250 different specimens of galls and the insects producing them. Mr. Westwood exhibited at the Entomological Society's meeting, March 7, 1836, specimens of Poppy-heads, destroyed by the attacks of a small Cynipideous insect.

Southwark, Oct. 20, 1836.

J. H. F.

(To be continued.)

[Our Correspondent's notes on Rennie's popular compilations, are interesting and useful; though they contain some facts and opinions to which we cannot ourselves subscribe.-EDS.]