These bodies (the chalaza) contain a spiral filament, the elasticity of which is so justly proportioned to the force by which the yolk is borne up, as to restrain it at a given point, and allow sufficient space between the yolk and the inner lining membrane, for the white to lubricate the surface of the yolk, and thus protect the germ from injury.'

Sir C. Bell's engraving accurately pourtrays this thin layer of albumen over the germ, but he does not attempt to account for it. His chalaza, too, correspond with this restraint on the buoyancy of the yolk, but he appears never to have contemplated a similar restraint under a reversed state of the yolk-bag.

We have mentioned that between the third and fourth day of incubation, the yolk appears flattened, and the albumen begins to be mixed with it. This is a settled fact, but the cause has long been disputed; and unless Mr. Towne has succeeded in explaining it, it still remains a questio vexata. Dr. Prout, in an elaborate paper in the Philosophical Transactions, proves the difference in the constitution of the white, which he found impregnated with foreign matter derived from the yolk, and which he termed modified albumen. Dr. Prout very honestly declares that it is left for some future inquirer satisfactorily to elucidate the manner in which this union takes place. Leveille made the chalazæ into absorbent vessels, to conduct the white into the yolk-bag,-a gratuitous piece of imagination. The Germans, who, we believe, have led the prevailing theory, ascribed it to the principle of endosmosis, a phenomenon first observed by Dutrochet. By this process two fluids of different specific gravity, acquire the power of commingling through an intervening septum of membrane or other substance. Several objections might be brought against this very ingenious and plausible explanation, which, however, we forbear to mention, as we are confident Mr. Towne's demonstrations on this point will for the future, perfectly supersede and exclude it.

'I

Mr. Towne quotes Sir E. Home's explanation of the cause of this communication, which is to the effect that a slit is made by the escape of the vesicle (chorion) from the internal opening, which leaves a free channel for the ingress of the albumen. 'confess from the first,' he says, this description appeared to me 'unsatisfactory; for admitting the existence of such a slit, I am 'at a loss to understand how the white, which is the heavier, and 'consequently always occupying the lowest part, should pass through it; and again, if this point be ceded, surely the same 'slit which admitted of its passing into the yolk-bag, would, on 'the egg being turned, also allow it to pass out, and then there 'would be an admixture of yolk and albumen external to the 'yolk-bag, a circumstance which never happens.' This slit was one of Sir Everard Home's day-dreams, having no real existence

-one which was bunglingly suggested to account for a phenomenon, about which he was perfectly ignorant. Sir E. Home was prone to imagine when he ought to have been observing, and his evil genius did not forsake him in this instance. He has not, however, given form or figure to his dream-a sort of maturity in the art of philosophical delusion which his plates and letterpress occasionally exemplify.

We cannot persuade ourselves to abridge Mr. Towne's account of this process, every portion of which we have since verified. He first noticed the sudden change in the yolk between the third and fourth day.

'It had lost its rounded form, become very pale, and was perfectly flat.' 'I was thus induced to direct my attention to the changes occurring about this period, and on turning out the contents of an egg that had been submitted to sixty-nine hours incubation, I found on the lower part of the yolk, or that opposite the embryo, a white line, describing a circle nearly the size of a half-penny; and on proceeding with the investigation remarked that as incubation advanced, the yelk-bag within this circle became clouded, attenuated, and wrinkled. By carefully watching and examining a great many eggs, I at last found one where the yolk-bag was ruptured within this circle; the white, however, in this egg had not passed through the opening, nor had the yolk lost its form.

'I have already stated,' continues Mr. T., 'that there is constantly until late in the process of incubation, a portion of thick whtie adhering to the lower part of the yolk-bag. I carefully dissected this off in a goose-egg of fifteen days, when a great part of the contents of the yolk-bag immediately escaped. I could now discover that there was ana tural opening in it, larger than a shilling, and this was skirted by a vessel in which the other vessels of the yolk-bag terminated, rendering the boundary of the opening so strong that I could readily introduce my finger and withdraw it; which I did repeatedly without its giving way.'

The same phenomena were discernible in a hen's egg.

From all this I infer,' says Mr. T., 'that between the third and fourth days of incubation a rupture takes place in the membranes of the yolk, at that part opposite to the embryo, through which the thin white passes, and immediately mixes with the yolk, while the thick white sinks to the bottom, becomes more dense, and securely seals the opening this may be seen in all its stages. At first the opening is large, and there is then a proportionate quantity of thick white, by which it is plugged. It next becomes surrounded by a vessel which contracts, thus reducing the size of the opening; and as it does so, the thick white is received within the yolk-bag until, in the hen's egg at the thirteenth or fourteenth day, the white has nearly all passed into

the yolk-bag, the opening has entirely closed, and a very small portion of slimy matter is all that remains external.'

By referring to the colored plate accompanying this description, our readers will readily form a distinct conception of this remarkable process; and a little careful manipulation in the dissection of a goose or hen's egg will reveal to them the far more interesting sight of its actual state. The gradual diminution of this opening by the contraction of the marginal vessel may be followed out, and the plug of thick albumen may be withdrawn, leaving this opening with its edge clear and distinct.

But Mr. Towne has assigned another function to this thick white. We have already dwelt upon the mechanism by which the germ is kept at the upper part of the egg, which we found admirably suited for the purpose, during the first days of incubation. But when the white becomes mixed with the yolk, the character and relative position of the several parts are altered, and so far as the buoyancy of the yolk, the attachment of the chalazæ, and the spiral filament are concerned, it seems to me,' says Mr. Towne, that the embryo might sink to the bottom; 'yet after this period the chick is still found at the upper part of 'the egg.' How, then, is it retained there? Mr. Towne says, May not the condensed albumen, to which I have alluded, sink to the bottom by its own gravity, and thus cause the embryo, 'which is exactly opposite, to rise to the highest point?'

6

We are much surprised that our author has not enlarged on this section of his paper. The interrogatory we have just quoted is all the account we hear of this function-one which our own observation has assured us to be correct. No sooner is one process destroyed, than nature ever fruitful in expedients though frugal in means, contrives another out of the ruins of the old; and while the change she designs is securely carried on, she appropriates the very source of the annihilation of the former mechanism, to create a new provision which shall fully supersede it. It is thus that, when the yolk-bag is so altered by the admixture of the albumen as to render the chalazæ of no further avail, the thick white is always fixed at the lower portion of the shell; and by retaining this position in every movement and rotation of the egg, it effectively keeps the little chick in the upper part of the shell. Coupling these two discoveries of Mr. Towne's together, we regard them as among the most interesting of modern physiology. Nor do they lose any of their worth from the very modest and unpretending way in which they are recounted. He has cleared many obscure points on this subject, and has developed many new ones; and, as we have shown, has succeeded in elucidating that which had hitherto baffled the observation of many eminent men; but we never hear the tone of exultation,

VOL. VII.

none of the triumphant Archimedes cry of ευρηκα-ευρηκα. We rather doubt whether he has protected himself sufficiently against the encroachments of those who watch their opportunity to filch away the researches of others. Certainly he has not so enlarged them, in their obvious bearings, as to prevent an easy and fruitful harvest for any whose slothful nature would induce them to prey upon their confines, and gain the second-hand reputation of being discoverers. There is an ambition very rife among the professors of science, to purchase fame and reputation with other gold than industry and research-an ambition which often leads. to immature views and incorrect facts, and entails and perpetuates error. We have seen something of this in the contributors to the natural history of the hen's egg; and had not Mr. Towne determined at the outset to take nothing as proved, we should probably still have been the supporters of Sir E. Home's erroneous opinions. We hardly know to what motives we ought to refer a dereliction from strict fidelity in describing the results of scientific investigations. Wilful misrepresentation we would fain believe, but rarely pollutes a scientific character. It may probably with more justice be ascribed to a proneness to be influenced by preconceived notions, so that things and appearances which are revealed to the senses are distorted and made to square with them. The imagination is thus pressed into service, and becomes the obsequions and ready abettor of the mind's bias, and hence it is that small bands are multiplied, elongated, and directed, when the prevailing idea is, that a yolk ought to be anchored down; and a small slit or an absorbent vessel are fancifully suggested to accommodate the admixture of two fluids. Personal vanity too must have its incense; and its cravings are not satiated until it can appropriate the titles of author or discoverer. An ambition for posthumous distinction, too, might be cited as an incentive to authorship; and the restless agitating impulse to do something leads oftentimes prematurely to productions in which recounted facts need the authenticity of long and laborious investigation, and, consequently, science the tribute of ultimate and irrevocable data. The non omnis moriar is the high aim of such persons, a sort of transition estate between earth and heaven, one which if administered to in the true spirit of philosophy will ensure its full reward, but if secured at the expense of faith and honesty-though the flaws and errors be well concealed -will quickly go the facilis descensus, reaping ignominy and reproach.

We cannot take leave of Mr. Towne without strongly urging him to pursue the subject more fully. We feel quite sure that he has yet much remaining which will enrich our present knowledge of the changes in the incubated egg and a future number of the Guy's Hospital Reports. Nor should we be discharging our

duty or our inclination were we not favorably to notice the colored plates appended to the paper. We hardly recollect to have seen any more faithfully and admirably executed, and which so clearly illustrate the subjects of the text.

Art. VII. The History, Antiquities, Topography, and Statistics of Eastern India; comprising the Districts of Behar, Shahabad, Bhagulpoor, Goruckpoor, Dinajepoor, Puraniya, Ronggopoor, and Assam, in relation to their Geology, Mineralogy, Botany, Agriculture, Commerce, Manufactures, Fine Arts, Population, Religion, Education, Statistics, &c. Surveyed under the Orders of the Supreme Government, and Collated from the Original Documents at the E. I. House, with the Permission of the Honorable Court of Directors. By MONTGOMERY MARTIN, Author of the History of the British Colonies,' &c. In Three Volumes. London: Allen and Co.

THE

HE time must be near at hand when the interests of that vast province of the British empire whose population is at least five times that of the British isles, and more than a hundred and twenty times that of our West India colonies, will stand revealed to the awakened attention of the public in this country in all their magnitude and importance. Hitherto, of the awful responsibility which the possession of India involves, not only do our statesmen and legislators appear to be insensible, but no adequate idea is generally entertained even by the philanthropic and religious portion of the community. How is this? The explanation is, we think, not difficult. First, India is regarded as a possession, not as a part of the empire; not as a colony. The number of British settlers is at present very inconsiderable, and few indeed emigrate to India with the intention of making it their adopted country and home. Then the natives are further removed from our sympathies than even the negroes or aborigines of our colonies, because the latter, at least to a considerable extent, are brought under moral cultivation, are as it were domesticated, Christianized, and speak our language. Once more, a certain degree of information is requisite in order to waken curiosity; and scarcely enough is known about India by the generality of persons, to lead them to feel interest in extending their knowledge. In fact, we believe that ignorance, absolute and discreditable ignorance, is the chief cause of the prevailing indifference to a subject which, when fairly appreciated and steadily contemplated, oppresses the mind with its vastness of extent and incalculable importance. And this ignorance, extending as it does