that he can attest the fact in the case of the islands in the northern lakes. If this be true, as I doubt not, the Havergate hares do not perform such an extraordinary feat as is supposed, when it is asserted that they cross a current, by no means "rapid," at certain stages of the tide, and certainly not so wide as S. V. W. makes it. I wish S. V. W. had gone to Havergate; he might have seen there a more interesting thing than a multitude of hares, and a "formidable aqueous barrier" to keep them from playing the truant: he would have seen what, to a geologist, as he is, would be a pleasing subject of consideration, the unfailing spring of water which bursts up from an immense depth below the island, and which is affected only by the changes in the level of the "barrier" aforesaid. After the hares have been well digested, our differences may be washed down by a draught from the said spring; but at present I must leave that phenomenon to a more fitting occasion. The only difficulty touching the hares is in the saltness of the water about the island; but salt is good to season criticism withal, as well as to keep hares from becoming amenable to the vagrant act; and, so that S. V. W. is satisfied that I do not mean to hoax your readers, I do not care, if, in a punning humour, he says of me, in the words of Plautus, "Nec quisquam plus salis, plusque leporis habet." * — W. B. Clarke. Brussels, May 13. 1831.

P.S. I have only just seen your Eighteenth and Nineteenth Numbers, or I would sooner have requested you to correct a few typographical errors in the letter in Vol. IV.; such as, p. 190. Leonhard for Lemhard; p. 191. Layham for Logham, &c. - I. B. C.

Hares taking the Water.-Your more recent Numbers have come to hand; and I beg to thank your correspondents for helping my unhappy Havergate friends over the stile of S. V. W.'s criticism. I hope he will now spare the "sauce piquante" of his facetious humour, and let my nautical hares take their place on your editorial table, to be dissected and swallowed according to the direction of good Mrs. Glasse, who, when she ordered that "hares" should first" be caught" before "cooked," doubtless never dreamed of shutting them up in an island by way of saving the sportsman the trouble of running after them. Had the Magazine of Natural History been in vogue then, she would probably have written, "First shut up your hares in Havergate Island, and then you can catch them ad libitum, and having caught them," &c. &c. &c. I suppose nobody believed Belgians could run, till the other day, when they stretched their legs at Louvain; but in these days of reform, we shall soon hear of greater wonders than swimming hares or flying soldiers, or of other people as easily mistaking as your exinsular correspondent.— W. B. C. Brussels, Oct. 15. 1831.

Eggs containing Chicks not to be successfully hatched if suffered to cool. — I am exceedingly obliged to your travelled correspondent, Mr. Waterton, for his attempted correction of my supposed mistake about hatching, truth being always preferable to hollow authority; but he can know little of me when he represents me as a book naturalist, deficient in "bog education." (Vol. IV. p. 517.) Had Mr. Waterton, however, spent a little more time" amongst books" than "in bogs," he might have learnt a little more accuracy; for his facts brought to prove my errors" are too vague to support any inference. If he means to say that eggs with chicks in them can be left till they are "cold as any stone (what degree of the thermometer he does not say), and then successfully hatched, I should advise him to take out a patent for hatching eggs without heat. No practical naturalist will credit the fact. Every naturalist knows that the terns, &c., leave their eggs for whole days uncovered; but then it is in very warm weather. I cannot pretend to have travelled as extensively as he; but so far as I have had opportunities, I have been, not a book but a field naturalist,

* "No one has more of salt [mirth] and hares [pleasantry].”

and constantly make excursions, as often as my very limited income permits. With all your correspondent's opportunities, it is to be lamented that he has hitherto published nothing respecting the economy or faculties of animals of the least use to natural history. If he will take my humble advice, before he publishes any thing else on hatching, he will provide himself with a good thermometer and a stop-watch.-J. Rennie. Lee, Kent, Nov. 3. 1831. [Mr. Waterton uses a watch in his observations: see p. 13.] Eggs when covered and moistened more easily hatched (Vol. IV. p. 517.). - Possessing but very little ornithological knowledge, and certainly without having profited by the advice of Mr. Waterton, of journeying to the East to consult the vizier of Sultan Mahmoud, learned in the language of birds; having, too, wandered amidst the bogs, rather in search of plants than to study the habits of the feathered race, and therefore knowing better the haunts of the pale pimpernel (Anagállis tenélla) and the ivyleaved campanula (Campanula hederacea) than of dabchick or waterhen, it may seem presumptuous in me to venture a suggestion respecting the covering of their eggs by certain birds when leaving their nests. I know not whether this habit is peculiar to water birds, or whether it is done by all, or nearly all, of the Linnæan orders Grállæ and Anseres, as in this respect my knowledge is limited to the tame duck and the goose; both of which, particularly the latter, cover their eggs with the greatest care. May not this be done rather to prevent the shells from becoming too much hardened by exposure, than for the purpose of keeping them dry and warm, as suggested by Mr. Rennie, in the passage of his work quoted by Mr. Waterton? I believe these shells are naturally hard and thick; and it is a fact well known to the rearers of these birds, that unless they have whilst sitting free access to water, and can return at intervals with moistened plumage to their nests, the embryo chicks find it impossible to break their shelly enclosure, and consequently perish: to prevent which fatal catastrophe, water is sometimes sprinkled over the eggs. It would not, therefore, appear that moisture is injurious to the embryo; but rather that, in the case of some birds, at least, it is a requisite in the process of hatching. I should, however, add, that when the eggs are thus sprinkled with water, it is always tepid, perhaps to resemble, as nearly as possible, the degree of heat it would imbibe from the bird whilst returning to its nest; and that it is also sometimes done, in very dry weather, to the eggs of the common fowl when the process of incubation is nearly completed. Whether doing so is, in all cases, the result of experience, and therefore right, or whether it is only a vulgar error, I leave to others more capable than myself to determine. C.P. Surrey, Nov. 1831.

Sir J. Byerley's Theory, which accounts for Geological Phenomena by the Precession of the Equinoxes. Sir, I have seen a very specious paper in Vol. IV. p. 308., by an old correspondent of mine, Sir J. Byerley, altogether in error in its reference to any doctrine of mine, and equally so in the doctrine which it assumes.

It is alleged that I promulgated the idea, that the geological changes arise from the precession of the equinoxes: but this I never taught; for the precession produces no physical effect, and no alteration of mechanical power; but merely carries back the nodes; and, with reference to the equinoxes, causes the stars apparently to move forward, or in about 25,868 years to go round the ecliptic. This was not my idea: but I taught that the geological changes arise from the advance of the line of apsides around the ecliptic in about 20,930 years, because the extremities of that line constitute the aphelion and perihelion points; and as in these the difference of distance is 3,000,000 of miles, so a difference of action and reaction arises, sufficient to cause the mobile waters to respect the declination of the perihelion, or point of greatest action. This theory I promulgated at some length in the Monthly Magazine, so long since as 1813; and I reprinted the same paper, as one of my Twelve Essays, in 1820.

Both these motions are very distinct, though they are only varied exhibitions of one very simple cause; viz. the necessary circumstance that every body which performs an orbit, as a consequence turns once on its own axis. The earth does so, and thereby gains on its own absolute orbit a space equal to its own circumference, adding a forty-seventh for the moon; and arrives at its nodes in the equator so much sooner every year than in the preceding, thereby creating the exact precession of the equinoxes. The same advance of the stars then carries forward the place of the apses by a proportionate quantity, insomuch that the earth's circumference + for the moon, is an exact mean proportional of the other two quantities. The times are 20,931, 23,190, and 25,868 years; the angles 50-1′′, 55-69′′, and 61·9′′; and the miles in space, 23,317, 25,426, and 27,724; whence it appears the sun's mean distance is 93,820,000 miles.

With reference to the detailed inferences of Sir John, and his friend Guesney, the whole is a whimsical error, arising from globe-makers locating an ecliptic for the practical purpose of determining declination; but the ecliptic of our terrestrial globes is not the ecliptic of nature, which having no terrestrial locality, all the deductions of those gentlemen are gross errors.

When astronomers say the pole of the equator goes round the pole of the ecliptic, they indicate no change in the oblique relations of the equator and ecliptic, but merely refer to the succession of the constellations by the precession or falling back of the nodes. This motion has no physical effect, because it is of no consequence whatever whether one constellation or another is vertical at the equinoxes; but the progression of the line of apsides has physical effects, because it changes the declination of the aphelion and perihelion points by 47°, and of course the direction of the least and greatest action and reaction.

If we want to know why there are tropical productions in northern climates, more than currents would warrant, we seem to have a cause in the narrowing of the obliquity, at the rate of a minute of a degree in 120 years, or a degree in 7200 years. If, then, this law is constant (but I suspect it is a decreasing series), 144,000 years would extend the tropics to the Alps, and 216,000 years would extend them to Liverpool; since which there would have been ten revolutions of the line of apsides, or transitions of the ocean from one hemisphere to another.

The cause of the inclination of the axis of a planet to its orbit is the inequality of its solid masses, the sphere being made up by the waters, but not the density, and the axis passing through the centre of density. The diminution arises from the constant force tending to bring the equator into the plane of the orbit motion, which is assisted by the action of water, air, &c., on the solid masses.

The whole of the celestial phenomena, as I have shown in every instance, are strictly mechanical, and subservient to the ordinary laws of mechanics, without any attraction, gravitation, or other superstitious fancies: but my present purpose is to rescue myself from the mistakes of Sir John Byerley and M. Guesney. They could not have read the essays which they quote, and probably have not seen my protest and supplement. I am, Sir, yours, &c.-R. Phillips.

"Wilson, the Ornithologist," did not die "a short time since," as stated in your last (Vol. IV. p. 558.), but in 1809. — J. Rennie. Lee, Kent, Nov. 3. 1831.

Mr. Alexander Wilson was born in Renfrewshire, Scotland, on the 6th of July, 1776; emigrated to the United States in the year 1794, and died in Philadelphia, of the dysentery, Aug. 23. 1813, aged 47. — John Perry. Manchester, Nov. 23. 1831.

[The first correction dates Wilson's death 1809; the latter, 1813: which is right?

ART. IV. Queries and Answers.

THE Chough of Cornwall (Pyrrhocorax Gráculus Temminck, Corvus Gráculus Lin.). Sir, In Camden's account of Cornwall, the chough (Corvus Gráculus) is thus described :-"In the rocks underneath, and all along this coast, breeds the Pyrrhocorax, a crow with red bill and red feet; not peculiar to the Alps, as Pliny imagined. This bird is found by the inhabitants to be an incendiary, and very thieving; for it often sets houses on fire privately, steals pieces of money, and then hides them. Can any of your correspondents in that county inform me how this bird became subject to the charge of arson, and whether it is really as mischievous as above described?

-J. A. H.

Is the Woodlark of White the Alaúda arbòrea of Shaw? Sir, White, in his Natural History of Selborne (as published in Constable's Miscellany), p.88., refers to the woodlark, as in the following lines:

"While high in air, and poised upon his wings,

Unseen, the soft enamour'd woodlark sings."

"In hot summer nights, woodlarks soar to a prodigious height, and hang singing in the air." Is the woodlark of White the Alaúda arbórea of Shaw?-E. H. Greenhow. North Shields, Sept. 22. 1831.

The Ràna esculenta (Eatable Frog) in Forfarshire. Sir, In the late Mr. Don's account of the plants and animals found in Forfarshire, it is asserted by the author (p. 37.) that a few of the eatable frogs (the Ràna esculenta of Linnæus) are occasionally to be met with about the lakes in that district, although rather rare. It is much to be desired that any of your readers, who may have it in their power to visit that county, would endeavour to verify this point by further enquiry and observation; since it is the only instance, of which I am aware, of a native locality being mentioned for this species of frog, whose claims to a place in the British fauna have been considered somewhat doubtful. If they should be so fortunate as to discover the animal, either there or in any other part of the country, perhaps they will be kind enough to make the fact known through the medium of your Magazine. The eatable frog is distinguished from the common sort principally by its larger size, and by the presence of three longitudinal yellow lines on the back. I am, Sir, yours, &c.-L. J. Cambridge, Dec. 2. 1831.

Reptiles in Ireland. Sir, H. N. has communicated (Vol. IV. p. 269. 452.) some account of the birds and quadrupeds found at and near Londonderry. Can he give me any information with respect to the reptiles of that neighbourhood? I have heard it asserted that there are no animals belonging to that class to be met with in Ireland. Can he from personal observation contradict this statement? and, if so, will he be good enough to add what species have occurred to his notice in that country? I am, Sir, yours, &c. - L. Jenyns. Cambridge, Dec. 2. 1831.

Agronome, who has resided some years in Ireland, states (Vol. IV. p. 557.), as the result of his experience, "There are neither toads in Ireland, nor snakes to eat them; neither did I ever see a mole there."

Remarkable Appendage to the Eye of Staphylinus hirtus. — Sir, I have read with much interest the pleasing and instructive communications of Mr. G. Parsons on the visual organs of insects and Crustacea. (Vol. IV. p. 124. 220. 363.) Having lately captured a Staphylìnus hírtus, upon the eye of which is attached an appendage (to me) of unusual occurrence, I shall endeavour to give as plain a description of it as possible, in the hope that Mr. Parsons, or some of your numerous correspondents, will inform me, through the medium of your Magazine, if it is of frequent occurrence; of

its supposed use; or if only accidental. Fig. 38. is a front view of the eye magnified. a, The transparent cornea, through which is seen the numerous lenses; b, the margin of the eye; c, an attachment, round, and thicker than any other part, the base of which is somewhat spread upon the surface of the cornea; d is about three times longer than c, but about half as thick; e is a sort of knob attached to the end, and half as thick again as d. Fig. 39. is a side view of the same eye.-D. N. Worksop, July 20.

1831.

Microgáster glomeratus. — We have had the pleasure to insert several previous contributions to the history of this interesting little insect. That by T. H., Vol. III. p. 50—52., with its figures, is rich in information respecting it; but that gentleman had the misfortune to apply to the insect the name of Ichneumon or Platygáster ovulòrum, which, of right, belongs to a distinct species. Out of this misnomer arose, however, the benefit of Mr.Westwood's scientific correction in Vol. III. p. 452., where, in connection with that correction, valuable information is supplied on the Ichneumonidæ generally. Mr. Morgan asks a question about this insect in Vol. III. p. 476. under the title of "Flies and Butterflies;" and Mr. Westwood replies to this question in Vol. IV. p. 95. under the title of " Mr. Morgan's Worms." To the same question our esteemed correspondent Mr. Bree also supplied an answer, which, by an almost unpardonable mistake, we inserted in the Gardener's Magazine, vol. vii. p. 121. We know no better mode of correcting our error than to reprint the article into this Magazine, that the communication may follow in its due order, and be seen by such of our readers as are not accustomed to peruse both works. Greenish black-marked Caterpillars on Cabbages. In your last Number (Vol. III. p. 477.) Mr. Thomas Morgan puts a question concerning a "number of minute eggs" enveloped in a silky substance, and apparently produced by the greenish and black-marked worms found on cabbages." Presuming that by "the worms" described he means the caterpillars of Póntia brássica (large garden white butterfly), which I have no doubt are what he alludes to, I feel no hesitation in referring "the minute eggs" to the pupa of a well-known small parasite called Microgáster glomeràtus (Ichneumon glomeràtus of Linnæus), of whose operations I extract the following account from Insect Transformations, p. 61, 62., where a figure of the insect will be found in its different states, together with that of the caterpillar on which it preys. The insect has also already been figured in your Magazine (Vol. III. p. 52.) under the erroneous name of Platygáster ovulorum as shown at p. 452. of the same volume. “It must have occurred to the least attentive observers of the very common cabbage caterpillar (Póntia brassica), that when it ceases to feed, and leaves its native cabbage to creep up walls and palings, it is often transformed into a group of little balls of silk, of a fine texture, and a beautiful canary-yellow colour; from each of which there issues, in process of time, a small four-winged fly (Microgáster glomeratus Spinola), of a black colour, except the legs, which are yellow. By breeding these flies in a state of confinement, and introducing to them some cabbage caterpillars, their proceedings in depositing their eggs may be observed. We have more than once seen one of these little flies select a caterpillar, and perch upon its back, holding her ovipositor ready brandished to plunge between the rings, which she seems to prefer. When she has thus begun laying her eggs, she does not readily take alarm; but, as Reaumur justly remarks, will permit an observer to approach her with a magnifying glass of a very short focus. Having deposited one egg, she withdraws her ovipositor, and again plunges it with another egg into a different part of the body of the caterpillar, till she has laid in all about thirty eggs. It is not a little remarkable that the poor caterpillar, whose