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an extended biography of the late Professor E. Forbes, for which purpose all the papers and information necessary, will be placed at his disposal by the family, and will, we trust, also be afforded him by the friends of Forbes generally. The biographer of John Reid and of Cavendish will, we are satisfied, execute the task with all that elegance and judgment characteristic of his literary productions, urged thereto as he is by a sincere friendship and look and intimate acquaintance with the subject of his memoir.

THANKS OF PARLIAMENT TO THE MEDICAL Officers or THE ARMY AND Nary:The Minister of War, in proposing the thanks of the country to the army, observed of the medical officers (especial allusion having been made to Dr Thomson),_“I must say, my Lords, that if it has not been usual for Parliament to thank such men as these, I consider that it is not wrong for a Minister of the Crown in this House to acknowledge their services." ("- Hear, hear," and cheers.) When Lord Palmerston does think it expedient to fulfil his promise, and put the medical profession in this country on a proper footing, it will be better for the public, as well as the civil services. Then it will not be unusual for the medical officers of the army and navy to be treated in every respect like their equals in rank.

HENBANE CIGARS.—Dr Seifert of Vienna, from personal experience, reconimends, in some chest affections, the use of cigars containing a proportion of henbane leaves—the Hyosciamus Niger. He directs these medicated cigars to be prepared in the ordinary manner from tobacco deprived of its acrid principle, to each of which from five to eight grains of the powder of the leaves of the common henbane are to be added. He states that patients may smoke from four to eight such cigars daily.Dublin Med. Press.

DROPPING Fluids from Vials.-Dr Coale has found a very simple and ready means of dropping fluids from vials. Unless the lip projects very much, the fluid is apt to run back on the neck, and remain attached until several drops have accumulated. Greasing the neck of the vial (not the lip will prevent this, and give a clean uniform drop.--Proceedings of Bosto! Med. Society.

ROYAL MEDICAL SOCIETY OF EDINBURGH.-The following gentlemen hare been elected office-bearers for the Session 1854-55 :-Presidents-John Jardine Murray, Robert Rhind, Henry Marshall, David B. Smith. Curator of Library --Almeric W. Seymour, B.A. Cantab Sub- Librarian-William Thompson. Treasurer-John F. Macfarlane. SecretariesJohn Somerville, William James Otto.

PUBLICATIONS RECEIVED. The Brain in relation to the Mind. By The Practitioner's Pharmacopæia and Pas

Joseph Swan, London. 1854. 8vo. Pp. 113. versal Formulary, etc. By John Foote. On the Construction, Organization, and M.R.C.S., London, etc. London, 185

General Arrangements of Hospitals for the 12mo. Pp. 368.
Insane. By Thomas S. Kirkbride, M.D., Remarks on the Examining Medical Boaru
Physician to the Pennsylvania Hospital for Indian Appointments, etc. By Jam**
for the Insane. Philadelphia. 1854. 8vo. Bird, M.D., F.R.C.S., etc. Londoi
Pp.80.

1854. 8vo. Pp. 15. Unsoundness of Mind in relation to Cri- The Piratical Specific. A New and Infil. minal Acts, etc. By John Charles Buck lihle Mode of Treatment for the Asiate nill, M.D., London, Physician to the Cholera. By Dr F. Wilson, of VanriDevon County Lunatic Asyluun. London, tius. London. 1854. 8.vo. Pp. 27. 1854. 12mo. Pp. 148.

We are obliged to postpone numerous papers and reviews until our next Number Professor Allen Thomson's communication has been necessarily delayed, from the line possibility of getting the illustrations really for the present Number. Dr Youngpapa! has been received,

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Part First.

ORIGINAL COMMUNICATIONS.

ARTICLE I.- Remarks on the Comparison of the Ovarian Ovum of

Birds and Mammiferous Animals. By ALLEN THOMSON, M.D., F.R.SS. L. and E., Professor of Anatomy in the University of Glasgow. Ever since the discovery of the mammiferous ovum by Von Baer, in 1827, some degree of uncertainty has prevailed among physiologists as to the nature and extent of the analogy which may be admitted to exist between its several parts and those of the bird's egg. With respect to the ovary itself no doubt prevails; for all appear to be agreed that, notwithstanding some differences of size and minute

structure, the pediculated capsules in which the yolks of the bird · are formed are essentially homologous with the Graafian follicles of

the mammiferous ovary. But the relation of the ovum to the ovicapsule is well known to be widely different in the two classes of animals; for in the bird the larger mass of the yolk, or ovarian ovum, completely fills the pediculated capsule, while in the mammal the spherical ovum, of very small size as compared with the follicle, lies embedded in the proligerous disc of the layer of granular cells which lines the Graafian follicle ; and the wall of the follicle, with the granular cellular lining, are distended by a considerable quantity of a clear fluid, which occupies the space within.

Von Baer regarded the large mass of the yolk in birds as the same with the cellular and fluid contents of the Graafian follicle in mammalia, and compared the whole mammiferous ovum—that is, the zona and parts within it—to the germinal vesicle alone (vesicle of Purkinje) of the bird's egg. The discovery, in 1834, of a germinal vesicle or germ-cell in the mammiferous ovum, similar to that of birds and other animals, withdrew the greater number of physiologists from V. Baer's view, and led them to consider the several component parts of the ovum, viz., the enclosing or vitelline membrane, the yolk substance, and the germinal vesicle, as corresponding or homologous structures in the two classes of animals. I have elsewhere shown that in this view they may have been carried too far, and that the tendency of more recent observation has been to demon

'Article Ovum of the Cyclopedia of Anatomy and Physiology, p. 77. NEW SERIES.-NO. II. FEBRUARY 1855.

strate that although a general correspondence may be admitted to exist in the structure of the ova of almost all animals, still there are so great differences among them that the establishment of an exact homology of their parts must in the meantime be abandoned. It is my object, in the following remarks, to point out what appear to be the most important circumstances of resemblance and difference between the parts of the egg in the bird and in the mammiferous animal.

Among vertebrate animals three different groups may be distinguished, according to the type of construction of the ova in each, viz., 1st, The oviparous animals with large yolked ova, and a limited germinal disc, such as birds, scaly reptiles, and cartilaginous fishes; 2d, Those oviparous animals, such as the amphibious reptiles and the osseous fishes, in which the ova and yolks are of middle size, with a more extended germinal part than in animals of the first group; and, 3d, The strictly viviparous animals, such as mammalia, in which the ovum and yolk mass are comparatively small, but the whole of the latter is germinal.

Of the three parts which form the essential component structures of the ovarian ovum in all these animals, the germinal vesicle is least subject to deviation from the general type, while the yolk or vitelline substance and the enclosing membrane both present considerable varieties. The following is a very general statement of the nature of these several parts and of their most marked differences in the several groups of animals above distinguished :

1st, The germinal vesicle or germ-cell is in all animals the original or first produced part of the ovum. In mammalia it presents the essential characters of a microscopic animal cell, varying in diameter in most instances from Tooth to both of an inch, and possessing within it a single nucleus, the so-called macula germinativa. In both the groups of ovipara it is of a much larger size (about ten times), varying from yooth to 3oth in diameter, or even larger; and in these animals also, the nucleus or macula, though at the very first production usually single, soon changes its character, so that during the greater part of its growth, and in the mature state, it is either subdivided into very numerous spots or nuclei, or becomes uniformly diffused as a fine molecular deposit in the fluid of the germinal vesicle.

2d, The name of yolk or vitellus, originally given to the yellow coloured substance of the fowl's egg, was for a long time indiscriminately employed, in all animals, to designate the whole substance which fills the ovarian ovum, excepting the germinal vesicle, and excepting also, in the larger ova of the ovipara, the cicatricula, or germinal disc, in the centre of which, when mature, the germ-cell is placed. The vitelline substance consists of oleo-albuminous ingredients, of which part is in solution in the clear fluid of the yolk, and part is in suspension in the form of molecules, globules, or cells of various magnitude, from the most minute point up to inch in diaineter. In the greater number of aniinals the solid or

both of all

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