vertebrates. The marine annulates farther resemble fishes in breathing by gills; a most beautiful and wonderful contrivance, which enables them to extract from water a sufficient quantity of air to aerate the blood, and thus precludes the necessity, so obviously attendant on all other modes of respiration, namely, a constantly repeated ascent to the surface for fresh supplies of atmospheric air. In these animals, consequently, the blood must ascend to the gills, in order to be brought into contact with the air so produced; but in the hexapod or true insects, which constitute by far the greater portion of the annulate kingdom, the respiration and aeration of the blood are managed on an entirely different principle.

The circulation of blood in hexapod insects we have already examined; let us now turn to the circulation of air. This is not confined to a single region, as the gills in fishes, or the lungs in man; but seems to be almost universal: it consists of an infinity of tubes ramifying through the body in every direction, from one end to the other. These air-tubes, termed tracheæ, have generally nine nearly equidistant external openings, termed spiracula, on each side of an insect. From each spiraculum a main trachea seems to enter the body, and immediately divides into two, three, four, or five minor tubes, one of which usually unites with the next spiraculum; thus forming a principal trachea, which extends the whole length of the body, on each side of the great dorsal channel for the blood already spoken of. From the main spiracular tracheæ minor transverse tracheæ frequently arise, and, passing above and below the great dorsal channel, unite with similar minor trachea, twigging off from the opposite side; and thus the whole system of tubes becomes connected, and acts by a common impulse.

To a casual observer, it may seem, perhaps, somewhat strange that a system of respiratory organs so apparently complicated should have been given to a race of beings which we consider of so very little importance in the universe: but an examination, however cursory, will show that here, as in every other of the Almighty's works, there is nothing superfluous; that there has been no labour in vain.

Respiration and circulation are so intimately connected, that the operation of each depends on the operation of the other. Now, in insects the blood is cold; and for this excellent reason, that, in so small a bulk as that of an insect's body, so large a portion of the blood is exposed to the air, that a heat superior to that of the atmosphere could not be maintained. This being the case, circulation of the simplest pos

sible kind was all that was required, and is all that has been given. It is well known that the blood of animals, when deprived of all communion with atmospheric air, stays in its course, and ceases to perform its functions. Now, by the simple system of circulation above described, it is evident that the blood could not be brought, with any regularity, to one particular spot, there to communicate with and receive air sufficient to renew and maintain its vital power. It becomes, therefore, a matter of necessity, that, as the blood does not go to the air to receive revivification, the air must be introduced to the blood for effecting that purpose. The most simple, the most direct, way of accomplishing this was by piercing the sides of the animal at regular intervals throughout its length, and inserting tubes through which the atmospheric air should pass with perfect freedom into the system, and mingle with the blood in any quantity that nature might demand. This is the very plan that we find has been adopted.

To this, the breathing of the marine annulates, already noticed, may be cited as an exception; it may be said that their blood is cold, and yet they breathe by gills. This is true; but it is also true that their residence in the depths of the ocean precludes the possibility of their using spiracula; we therefore find the system of their circulation raised, to cooperate with their improved respiration. It was quite needless that their blood should, farther, be warmed; for we find that even in fishes the blood is perfectly cold, for the same reason as in insects, because their bodies are (when young) too small to resist the temperature of the surrounding medium.

There are numerous aquatic annulates which belong to the hexapod or true insects, which are provided with a system of respiratory organs precisely similar to that of the terrestrial insects; these have the power of enveloping, with a bladder of atmospheric air, those parts of the body in which their spiracles are situated; thus not only protecting the spiracles from receiving any injury from the ingress of the water, but keeping up the necessary supply of air to the blood. The bladder of air is renewable at pleasure by rising to the surface.*

(To be continued.)

Do not the sacs, within which trachean Arachnides have been found parasitic upon the aquatic Dytíscus marginàlis (see p. 161.) serve the same purpose as this "bladder of atmospheric air" serves to the aquatic hexapod insects? and, farther, all the cysts, with which a variety of animals parasitic upon aquatic animals are found covered? See VI. 94., for a notice of some parasites found encysted.-J. D.

ART. VII. A Statement of the Quantity of Rain which has fallen at High Wycombe, Bucks, during the last Ten Winters, with Remarks. By JAMES G. TATEM, Esq.

THE table beneath shows the quantity of rain which has fallen in this place, in the months November, December, and January, during the last ten winters. It may serve to correct the general impression, that more rain fell during last winter, than had fallen in any winter of several preceding years.

From this table it appears, that, in the winter embracing 1827-28, rain fell to the amount of 11.435 in.; while, in the winter which is just closed, only 10-925 in. of rain have fallen giving an excess of upwards of half an inch to the former period. The great difference has been, that rain has fallen more frequently in the last winter (namely, on 63 days); while, in that of 1827-28, rain fell only on 55 days: and to this circumstance may be attributed the prevalent opinion.

That great humidity of atmosphere is constantly attended by a high degree of temperature, is well known to every meteorologist; but the mildness of the last three months, or brumal quarter, was most extraordinary. In the brumal quarter of 1827-28, the mean temperature was 40.10819°, which was very much above the average; and the extremes were 56° and 15.50°. In the recent one, the extremes were 58° and 24°; and the mean 41.87835°: the extremes occurred in November in both instances. Out of 92 days comprising the quarter lately expired, the wind blew from the westward on 72 days; but, in the brumal quarter of 1827-28, only on 60.

It is curious to observe, that the greatest quantity of rain fell when the extreme of cold was experienced in the month of November; and it is only by the record of observations like these, that the meteorologist can hope to promote a science (of the greatest importance to mankind) as yet in its infancy; and possessing but few of the charms which captivate and allure the student in other sciences, cheer him in his course, and reward his toils.

ART. VIII. Short Communications.

THE Fox and the Dog have been known to feed upon Fish.— That foxes feed on fish is, I believe, a fact hitherto unknown to naturalists; at least, speaking for myself, during a life of many years devoted to the study of natural history, I have never heard of it. That it was not impossible, however, I should never have doubted, from a curious corroboration of its possibility, which happened more than once under my own observation. I occasionally took out with me in a boat, when fishing, a small terrier of the Scotch breed. One day, having caught three or four dace, after some minutes I turned round to examine them, when, lo! they had disappeared; and I could in no way discover the cause. Shortly I caught another, and threw it down, when, to my great surprise, the dog quietly took it up, and (after very composedly craunching its bones) swallowed it with apparent satisfaction, and then looked up with a hungry eye, as if to request a farther supply. As far as I can recollect, the dog ate about half a dozen before any symptoms of " hold, enough," were manifested.

Now for the fox; whose case, though it depends upon circumstantial rather than positive evidence, I have no hesitation in believing to be perfectly true. In the course of last autumn, I believe, in October or November, a gentleman's keeper in my parish, in passing a pond very early, after a moonlight night, found upon the bank the remains of a pike which had weighed about 5 lbs. The flesh was consumed, with the exception of what adhered to the head and tail. The fish he was well acquainted with, having often noticed it before, and during the preceding summer had as often, in vain, endeavoured to take it by night lines, &c. Of course, his first thought was, "how got it there, so strangely out of its element?" A poacher would certainly not have left it. Fishing eagles had never been seen or heard of in this part of the country; and otters had long been an extinct race in the neighbourhood. But, on closely examining the mud and soil, he soon discovered a clue to solve the mystery; the adjacent parts being padded with footmarks, which his long and practical experience convinced him were those of a fox. It is probable, too, that, like himself, the fox had long had an eye to this well-fed pike, as it then occurred to him, that he had often before seen similar footmarks about the pit side banks. To have witnessed the capture would have been an interesting scene indeed. It is most likely that the wily animal, on examining the water, discovered the pike near the surface, prowling about for food, and, availing himself of its approach

ing within reach, pounced upon his prey, and succeeded in grasping it with his teeth; this, however, he could not have done without considerable tact and difficulty, as the floundering resistance of a five-pounds'-weight pike must have lasted some time, and been very powerful.-E. S., F. L.S. [For notes on other habits of the fox, see p. 134.]

BIRDS.-The small dark brown Thrush notified by W.L.(p.144., and previously); with some Remarks on the British Thrushes."It is much to be wished," as the Rev. W.T. Bree has observed (p. 75.)," that W. L. had procured a specimen of his thrush, in order to put the point beyond dispute;" for, until this is done, it seems somewhat premature to pronounce it a distinct species. The common song thrush varies in size very considerably, and in the number of black spots upon the breast. Of two males now before me, both in tolerably good condition, one weighs 2 oz., and the other but 2 oz. The former of these has remarkably few black spots on the under parts; whereas, some that I have seen have been so thickly studded that the ear-coverts have appeared wholly black. Lewin and others have even described, as a distinct species, what they call "the heath thrush;" which now is, I believe, universally admitted to be merely a small variety of the Túrdus músicus. I must be pardoned, therefore, for still entertaining doubts as to W. L.'s thrush being an undescribed species; first, because I know that the common song thrush (to which it seems so closely to approximate) varies in size very much; secondly, because the song thrush may often be observed upon the wildest heaths, and, in such situations, is generally small; and, thirdly, because so common a bird as that of W. L. appears to be, if really distinct, could not well have escaped the ken of the many experienced practical naturalists who have visited the parts it inhabits, seemingly so plentifully. However, I hope that W. L. will soon succeed in obtaining some specimens of his thrush, that he will actually compare it with the song thrush, and favour Mr. Loudon's readers with a minute description of its characters, that the matter may at once be satisfactorily set at rest, without farther cavil.

That the first notice of it (VI. 218.) referred merely to the redwing, was the opinion of many persons besides myself (VI. 516.), and was strengthened by the fact of no allusion having been made to this species; although its manners, as observed in the south of England, were pretty accurately portrayed: and which bird it further seemed to resemble in size. The redwing, it may be remarked, resembles much more the song thrush, in colour and general appearance, than it does the