discoveries appears so anomalous, so important, so intensely interesting, as that just made by Mr. Newport, of the external branchiæ of a perfect winged insect. It is well known that many of the same order of insects-the Perlites-possess external branchiæ in their preparatory stages; but an obvious reason exists for this, in the fact that in their earlier stages the Perlites are almost entirely aquatic; and this form of lung, so to speak, is admirably adapted for abstracting from the water the necessary supply of air: but it has been generally supposed that the only mode by which animals could inspire or expire atmospheric air, was by its entrance into or propulsion from internal receptacles through apertures in the outer covering of the body. This is not, however, strictly the case; for although it is common with isomorphous Neuroptera to spend the period of their preparatory states in the water, exceptions occur, and we find the immature state of a not uncommon Perla, secreting itself by hundreds in the crevices of the bark of pollard willows, when growing in districts abundantly intersected by running streams. The creatures appear very inactive by day, and crouch flat on their bellies, but probably at night they sally forth in quest of the insects which the bark of trees seems to attract. Be this as it may, these creatures, although no longer subaqueous or, supposing they resort to, the water by night, of which we have no evidence, at least not constantly subaqueous- yet retain an external apparatus for breathing very similar to that of their subaqueous congeners. Still we are prepared for this close coincidence between creatures of the same genus, and in the same states: but that an instance should have been found in which an entire genus carries this structure with it into its ultimate or imago state, seems to baffle all our researches for precedent, and present a feature in insect anatomy for which we are wholly unprepared. Many of our entomological readers will recollect the ingenious hypothesis suggested by Latreille, that the wings of insects were transmuted organs of respiration: the idea that the same organs would serve the double purpose of respiration and locomotion, is due, we believe, to the fact that such was actually the case with the external branchiæ of the subaqueous larvæ of Perlites and Ephemerites, the insect using its branchiæ as fins to propel it through the water. Mr. Newport's discovery places a direct negative on the hypothesis, since throughout the genus Pteronarcys the wings as well as branchiæ are invariably present, the wings occupyHe describes the ing the dorsal, the branchia the ventral surface.

branchiæ as follows.

“They are of the tufted or filamentous form of branchiæ. They consist of eight

pairs of branchial sacs, from the exterior of which proceed numerous elongated, setose filaments, which together form a thick tuft on each sac. These branchiæ are situated, as described by Pictet in the larva state of Nemoura cinerea, Pictet, over the proper spiracular orifices or entrances to the great longitudinal trachea of the body, at the inferior lateral parts of the thorax and basilar segments of the abdomen. The first pair of sacs is in the tegument of the neck, between the head and prosternum; the second and third pairs, each of which is composed of two tufts, between the prosternum and mesosternum, behind the coxæ of the first pair of legs: the fourth and fifth between the mesosternum and metasternum, behind the coxæ of the second pair of legs: and the sixth pair behind those of the third pair of legs, at the junction of the thorax with the abdomen. The seventh and eighth pairs, formed each of single tufts, are attached more laterally, the seventh to the first, and the eighth to the second basilar segments of the abdomen. These latter branchiæ correspond in situation in the segments to that of some apparently closed or obsolete spiracles at the sides of the succeeding segments. The situation of the branchiæ themselves is thus as anomalous as their existence in the perfect insect. In most instances branchiæ are arranged along the sides of the abdominal segments of the larva, and are often employed to assist in locomotion: but they cannot be of use for this purpose in the larvæ and pupæ of these Perlidæ, which move by means of large and powerful limbs. In Pteronarcys the two posterior pairs of legs of the pupa have the tibiæ densely ciliated, for swimming, like those

of the Dyticidæ, so that the delicate filamentose branchiæ can afford little, if any, assistance in this function. The structure of the filaments themselves differs also from that of the filamentose branchiæ of the Sialidæ, in which these organs are said to be quadri- or quinque-articulated, and are employed as organs of locomotion. In Pteronarcys they are simple unarticulated filaments. Each filament is soft, delicate, and gradually tapered from its base to its extremity, and ends in a slightly obtuse point. Internally each filament is traversed longitudinally by a tracheal vessel, which becomes, like the filament itself, more and more slender, and at last divides into two branches,

which may be traced to the extremity of the filament: but I have not been able to discover any orifice in the extremity of the filament, nor any direct communication whatever between the external surface and the ramifications of these trachea, and I doubt much whether any such direct communication exists."

Mr. Newport's specimen was brought by Mr. Barnstone in spirits from Canada, together with many other highly-interesting NorthAmerican insects, the whole of which have been presented by that gentleman to the cabinet of the British Museum. Mr. Barnstone, who appears much devoted to Natural History, paid great attention to the Perlites in their native localities, and made some highly interesting observations on their economy. He remarked that the so-called pupa of Pteronarcys regalis, in the state immediately preceding its attaining the power of flight, lived constantly in the water at the bottom of streams; while the corresponding state of Perla abnormis, - the largest species yet known of the genus Perla, - was invariably hidden in the clefts of water-logged timber, the trunks of trees and other places on the banks, and he has found its exuviæ under stones along the banks of rivers; thus closely corresponding in economy with the English species to which we have already alluded. Mr. Newport enquires whether any analogous discrepancy exists in the habits of the perfect insects of the two species. The species of Pteronarcys, as observed by Mr. Branstone, shun the light of day, hiding themselves under stones in damp places, and it is only at nightfall, when the air is charged with moisture, that they appear on the wing. In this respect, however, they differ but little from the true Perla of the old continent. It is a most interesting question, as proposed by Mr. Newport, whether this peculiar structure is a provision of Nature for the damp atmosphere in which the Pteronarcys generally passes its life, or whether the persistent branchia are accidentally retained, the functions of aëration being performed by other means. Mr. Newport observes:

"In regard to the function of aëration being performed by these branchiæ in the perfect insect, I may remark that it is of little consequence to the preservation of animal life whether aëration of the fluids of the body be effected directly, by means of air received into the body in lungs, or in spiracles and tracheæ, or indirectly, by means of water or vapour, that holds air intermixed with it, through the agency of external branchial organs, in which case the air is brought into contact with the fluids through the surface of these organs in water equally well as in the open atmosphere, when air is taken into the body through the spiracles. The function of branchiæ, or aquatic organs, is equally well performed in the open air as in water, so long as the air is charged with a sufficiency of fluid to preserve these organs in a healthy state."

We trust Mr. Newport will pursue the enquiry he has so ably com

menced, and we wish him every success; in the mean time he has our honest thanks for the boon he has conferred on the science of Entomology. The figure of Pteronarcys regalis was engraved for Gosse's 'Canadian Naturalist,' and has been most obligingly lent to 'The Zoologist,' to illustrate this paper.

Enquiries in Practical Entomology. I gladly embrace this opportunity to thank Mr. J. W. Douglas for his excellent description of the method of capturing moths with sugar; and to express a hope that other experienced metropolitan entomologists will from time to time favour their provincial and less experienced "brethren of the net with similar remarks on practical Entomology. The general usefulness of Mr. Ingpen's Instructions for Collecting Insects,' has been much impaired by omitting to give detailed descriptions of the method of constructing the apparatus, on the plea that there are now several shops in London where such can be procured; but no data are there given by the aid of which the rustic tyro, who perhaps has never seen these articles, can give the necessary directions to a tradesman. So little has Entomology been cultivated in Scotland, that there is not a shop, even in Edinburgh, where a single article, except the forceps, no, not even proper pins, are sold; but these can now be procured from London by post. My friend Mr. E. Brown has described a collecting-box (Zool. 177), the merits of which I have fully tested; and by his advice I have adopted the folding hoop of an angler's landing-net, which screws into a handle or walking-stick, and is fitted with three bags of different sizes, of gauze, coarse canvas and linen, and I have found it to be the best and handiest weapon of any. I should feel greatly obliged by some of your correspondents describing the best way of fitting up a lantern for mothing purposes, and also for a list of such flowers and shrubs as are most frequented by the pretty rovers of the night, that, if necessary, I may add them to our borders. Such practical hints are invaluable to every one that is seriously bent on self culture. For want of such knowledge how many sigh after returning from an unprofitable excursion, though undertaken at the sweet hours dedicated to silence and meditation, and mourn over the sad loss of time, of which, as Seneca nobly says, "It is a virtue to be covetous!"-Archibald Hepburn; January 9, 1844.

[In my Familiar Introduction to the History of Insects,' I have endeavoured to give the information required by Mr. Hepburn. I quote the observations on apparatus; those on localities, mode of collecting, &c. I would willingly transfer to these pages, but I cannot afford the space they would occupy.-E. N.]

"The principal instruments of the collector are boxes and nets. The boxes should be of mahogany, opening readily on brass hinges; length seven inches, breadth four inches, depth two inches; the top and bottom should be lined with fine soft cork, and covered with white paper. The pockets of a shooting jacket will readily carry three or four such boxes as these. Besides these boxes, there should be two long cylindrical tin boxes for the caterpillars of Lepidoptera: the tin not only keeps the caterpillars cool, but it causes the leaves on which they feed to retain their freshness many days. Tin boxes are also useful to bring home Diptera alive in this case a cylinder of tin passes through the lid of the box, and is corked at the top.

"The clap-net, represented at the head of this chapter, is the grand weapon of the entomologist. This is a large piece of muslin, four feet long and nearly three wide,

supported on two light rods, which pass along a border made of brown holland or other strong substance, bend towards each other at an obtuse angle, and meet at the top of the net. One of these rods is held in each hand, the handles being the parts uncovered; the net is fixed to each rod by means of a piece of tape, which passes through a hole made in the rod, and is tied firmly in a bow.

"The rods of the clap-net are each composed of five pieces united by ferules; when taken to pieces and placed in the net, the latter may be folded in a very moderate compass, slipped into a brown holland case, and put in the coat-pocket. For this kind of net both green and white muslin are used; but white is much the best, as the small insects are more readily distinguished on it; green muslin however has the merit of being less conspicuous, which under some circumstances is an advantage, for instance, in those country lanes where the pedestrians are unused to such an exhibition, the white net never fails to attract a little crowd, which causes some slight inconvenience to the entomologist, as well as loss of time, for he is invariably under the necessity of explaining to the by-standers what he is doing.

"This net is the best for pursuing butterflies and moths on the wing; the hunter tries to get the net under the object, and strikes upwards, closing the rods at the same time. A loose bag is formed, by a fold of the muslin, across the bottom of the net; this prevents anything from getting out. The same net is held in one hand under the boughs of trees, &c., while these are beat by the stick of the water-net held in the other hand; and thus, besides perfect insects, a great number of caterpillars may be obtained.

"The other nets used by entomologists are of many kinds; these two are the best: first, the forceps, with handles like those of scissors, with holes for the finger and thumb, and two circular or octagonal frames of iron, on which muslin or cheese-cloth is stretched. This instrument is particularly useful for taking the Diptera and Hymenoptera, which settle on umbelliferous flowers. The forceps should be kept in the right hip pocket of the coat, to afford a greater facility in taking them out when wanted to be used with celerity: but it must be borne in mind that this weapon is never to be trusted when insects are on the wing; because its size is so small that the object at which you snap is beyond your reach before the forceps can close, however correct your aim; and a repetition of the snap is seldom attended with better success.

"The second net is the water-net. It is composed of a strong hoop of iron, jointed so as to fold up in a convenient form; on this hoop is fastened a strong bag net, made of cheese-cloth; the hoop has a male screw, which fits a female screw at the end of a stout stick about four feet in length. With this instrument all water-insects are ta ken; the water straining off through the net, and the insects remaining at the bottom. "The same net, or a lighter one of similar form, screwed on a similar or the same stick, is called the sweeping net, and is used for sweeping grass, on which myriads of minute insects are always to be found: the weeds on the banks of rivers and canals are also excessively productive in insects, which can only be taken in this manner. In walking through meadows it will be found a good plan to hold this net in such a position that it may continually strike the projecting blades of grass.

"The entomologist should be provided with two wide-mouthed vials; one empty and perfectly dry, having a quill passing through the cork, and going a considerable way below it: this quill may be stopped at top by a second small cork: within the vial some blotting-paper may be kept, which not only absorbs any moisture, but serves as something to crawl on for the living insects which are taken from time to time and