or does not, happen," it is perfectly independent of any art; and we cannot, therefore, admit the justice of Dr. Meigs's assertion that the science of obstetricy comprises the arts of therapeutics and surgery as applied to sexual affections in women. These arts, again to use Mr. Mill's definition, are collections of rules, whose language is "do this, avoid that;" and therefore they cannot constitute a department of obstetric science, but belong to the art which is founded upon it. To include the whole of this art under the designation of midwifery, would be to make a wide extension in the application of that term; which is usually restricted to the care of the act of parturition, and its antecedent and consequent phenomena. To such an extension there are many obvious objections; and we do not see what else is to be done, than to distinguish carefully between obstetric science and obstetric art,-just as we distinguish between the science and the art of medicine or of surgery,-and to let midwifery continue to relate to that division of the art, which the term has hitherto been employed to designate.

Although we have not considered either of our authors very successful in the formal definitions, with which their treatises respectively commence, yet the distinction between principles and practice is most fully recognized by both in their teachings, as well as in their titles. In fact, Dr. Tyler Smith's object is to give to Obstetric Science a far higher elevation than it had previously attained, by connecting it with those general principles of Physiology of which a large proportion of obstetric practitioners, and too many obstetric writers, are profoundly ignorant. For his labours in this vocation he deserves great credit, whatever we may think of his success; and if we shall find it our duty, in the discharge of our critical office, to express our dissent from several of the doctrines which he has propounded in the treatise before us, we do not the less feel that he deserves the gratitude of the profession, for having pursued the study of obstetric science in a more enlarged spirit than any preceding writer, and for having diligently attempted to improve and extend it.-We quote his preface in full, as expressing what he conceives to be his claims as a discoverer, and as justifying the careful examination of these claims upon. which we shall presently enter.

"I began to study Reflex Obstetrics in 1842; and the present work is the result of seven years close and earnest attention to the subject. I may say truly, that during this time, though inuch occupied by other matters, it has scarcely ever been absent from my waking thoughts.

"I have no wish to deprecate criticism; but I trust I shall not be considered in the light of one who applies facts and principles already known to his own department of practice. I believe every candid person conversant with the current knowledge of the reflex function, and of obstetrics, when I began to write, must admit that I have both added to reflex physiology, and made extensive applications in practice, which had eluded previous observers. Indeed, reflex obstetrics is a new department of the reflex function and its applications. Taking the whole range of reflex physiology, the cause of labour is only second in importance to the cause of respiration; and no one had perceived that the relation of the ovarian nerves to parturition is the same as the relation of the pneumogastric nerves to respiration while, in the investigation of the causes of the Genesial Cycles, in the Twelfth Lecture, I have entered upon a new field, although distinct from the reflex motor function.

When I published my first 'Observations,' reflex physiology had not found

even a verbal home in any work on Obstetrics; but I do not think it will be possible to say the same of future works in this department of medicine." (p. viii.)

Dr. Tyler Smith's treatise, like the lectures already published in the 'Lancet,' of which it is almost entirely always made up, is much less an introduction to the study of obstetrics, than an exposition of the author's peculiar views; and is consequently less fitted for the pupil who needs a comprehensive text-book of the science, than it is for the advanced student, who is prepared by his previous acquirements to eliminate its truths from its errors, and to profit by the former without being led astray by the latter. As a treatise on the "Science and Art of Obstetrics," it is deficient in much that the pupil needs to be taught; as a dissertation upon "Reflex Obstetricy," it is replete with interest. The latter title would therefore, in our estimation, have been more appropriate than the former; and we shall discuss the subject-matter of the treatise as if it had been thus designated. This, in fact, will be the fairest method of procedure in regard to the author; for we are sure that he will be best satisfied by our bringing into prominent relief those portions only of his treatise upon which he bases his claims as a discoverer, passing by with little or no mention those which contain no distinct novelty. We shall find that the former will afford such ample food for critical discussion, as to necessitate our restricting ourselves in the present article to the theoretical portion only of Dr. Tyler Smith's work.

The corresponding department of Dr. Meigs's treatise presents so little that varies from the beaten track, that a few words will suffice to dismiss it, especially as we had occasion not long since to criticise some of Dr. Meigs's opinions on these subjects, as well as his manner of expressing them. With regard to the style of the present treatise, we have the satisfaction of informing our readers that whilst it presents many of the peculiarities which characterized Dr. Meigs's "Letters to his Class on Females and their Diseases," it is free from the most offensive faults which disfigured that work. The colouring is in fact considerably 'toned down;' and would perhaps be altogether not more lively than is sufficient to make the book very agreeable reading, were it not that the old affectations every now and then force themselves in, with somewhat unpleasant obtrusion. We noticed on a former occasion (Vol. III, p. 142,) Dr. Meigs's notion that the "corpus luteum" is a vitellary body. On this subject he expatiates somewhat fully in the present treatise; and informs us that, when boiled, the corpus luteum becomes hardened like yelk boiled hard, and that, when roasted, it gives out a strong odour of roasted eggs! From the result of this truly refined and trustworthy procedure, in addition to the microscopic observations formerly referred to Dr. Meigs deduces what we must regard as a most loose and unphilosophical analogy between the corpus luteum and the vitellus. Their similiarity in composition, histological and chemical, however close it may be, does not indicate any real analogy, their position and functions being so essentially different. A vitellus is not a vitellus because it is composed of albumen, oily matter, sulphur, &c., which the chemist finds in it; or because of the floating corpuscles which the microscopist detects; but because it is so placed within the ovum as to afford a supply of nourishment to the developing embryo, which shall be converted into its own textures. This is the essential idea of a yelk or vitellarv hd and to give the designation of

vitellary body, therefore, to a substance which is only developed after the ovum has escaped from the ovisac, and even on the exterior of the ovisac which enveloped the ovum, and having no function whatever as regards the embryo, appears to us a complete perversion of language.

We are surprised to find Dr. Meigs greatly behindhand in his knowledge of the structure of the placenta. For anything that his account of it contains, it might have been written ten or twelve years ago, when as yet neither Professors Weber, John Reid, or John Goodsir had unravelled its complicated arrangement. The old questions about the foetal and maternal portions of the placenta, are discussed in the old style; and the author gravely comes to the conclusion that the placenta is entirely a fœtal organ, and that the notion of the passage of vessels, or of maternal blood, from the uterus to the placenta, is all a delusion. He rests his convictions upon the evidence of his own senses, having on more than one occasion seen nothing but " mucous tractus" passing between the two surfaces when torn apart from each other, and having thus satisfied himself of the total absence of vascular communication. When he shall have prosecuted a dissection of the parts in question, under water, and with the requisite slowness and care (that of Dr. J. Reid occupied him several hours a day, for some weeks, we believe months); when he shall have followed, with Professor Goodsir, the development of the placenta, and shall have seen how it is made up of uterine tufts and decidual growth; and when he shall have microscopically examined the placental tissues, injected and uninjected, and shall have accounted for the presence of maternal blood in the placental cells, whilst the fatal blood is restricted to the tufts which constitute the ultimate subdivisions of the umbilical vessels; we will allow him to have an opinion of his own. Until then his assertion of the entirely fœtal nature of the placenta is altogether valueless, and he is bound to teach the opinions of those who have made such examinations. For our selves we can say, that having witnessed a considerable part of Dr. J. Reid's dissection, we can bear unequivocal testimony to the correctness of his results; and that having also gone carefully through the microscopical examination of the placenta, we can equally confirm the statements of Professor Goodsir in regard to the combination of foetal and maternal structures which it contains. Dr. Meigs lays great stress on the fact that the whole placenta is thrown off in the human female, instead of the fœtal portion only, as in the lower mammalia; but he takes no account of the circumstance that the decidua also, of which the maternal portion of the placenta is only a peculiar development, undergoes the same detachment. În regard to the real nature of the decidua, too, we are surprised to find Dr. Meigs apparently ignorant of the satisfactory elucidation which it has received in this country; he quotes M. Coste and other continental authorities glibly enough; but for him Professors Sharpey and Goodsir have observed and described in vain, and the decidua reflexa is still pushed before the advancing ovum as in old times.

We are sorry to be obliged to speak in these terms of Dr. Meigs's sins of omission. He takes up many other novelties with such delight and earnestness, that we are sure that he cannot be unwilling to receive information or correction; and we should therefore recommend him to work up his physiology a little better from the later general treatises in which these discoveries are embodied. We shall now quit him for the present, 7-IV.

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that we may devote ourselves without hinderance to the examination of Dr. Tyler Smith's production; in doing which we shall take leave to follow the order which best suits our purpose, not that which the author has adopted. This will lead us in the first instance to inquire into the muscular structure and nervous endowments of the uterus.

Muscular structure of the uterus.—It is not long since the muscularity of the uterus was a subject of grave discussion; the affirmative being maintained by some eminent authorities, and the negative by others. The microscope has now settled the question, by showing that the uterus is made up of fibres which belong to the non-striated kind of muscular structure, corresponding in this respect to the muscular coat of the alimentary canal. It has been affirmed that, towards the completion of the term of gestation, fibres of a faintly striped character, resembling those of the heart, are to be seen in the uterus; but in the unimpregnated state, the fibres bear a close resemblance to those of less elevated development. Nervous supply of the uterus.-Notwithstanding the difference of opinion which exists in regard to amount of the nervous matter of the uterus, all are agreed, we believe, that its nerves are immediately derived altogether from the sympathetic system. Dr. Tyler Smith, indeed, speaks of the uterus as "principally supplied with nerves, by the hypogastric and sacral nerves, and by branches from the spermatic plexus;" but this is a very loose method of stating the fact. The nerves of the uterus are all traceable-as Dr. Smith subsequently points out—either (according to Dr. Lee's views) into ganglia of its own, which form part of the sympathetic system, or into the ganglia and plexuses of that system from which the other pelvic viscera are supplied. No anatomist, so far as we are aware, has traced any branches of the sacral nerves into the uterus itself; although it is unquestionable that branches of several nerves of the cerebro-spinal system pass into the plexuses of the sympathetic, and are in that way distributed to the organ. It may be said that the distinction is unimportant; but we cannot regard it as being so; for it is obvious that the endowments of the cerebro-spinal fibres which enter other parts of the sympathetic system are greatly affected by their association with it, neither sensory impressions nor motor impulses being as readily conveyed by these fibres as they are by the ordinary cerebro-spinal nerves. So struck were the older physiologists with this fact, that (as is well known) they assigned to the ganglia the office of "cutting off sensation."

We are not about to offer any decided opinion upon the controversy which has arisen respecting the validity of Dr. R. Lee's claims to the discovery of additional nerves and ganglia in the virgin uterus, and of a great increase in the nervous supply during the enlargement of the organ in gestation. These claims are strongly advocated by Dr. T. Smith, who gives the following statement of them:

"Below the bifurcation of the aorta, the aortic plexus divides into the two hypogastric nerves. Dr. Lee describes the hypogastric nerve as forming, in its descent to the cervix uteri, the hypogastric plexus. This plexus, when it reaches the cervix, terminates in a large ganglion, which Dr. Lee has called the hypogastrie ganglion. The hypogastric ganglion is, in the unimpregnated state, on the authority of the same anatomist, from half an inch to three quarters of an inch in diameter; and is made up of numerous lesser ganglia with their rami of communication. Into the outer and lower surface of the hypogastric ganglion, numerous branches

enter from the third, and sometimes from the second and fourth cervical nerves. This ganglion, thus composed and reinforced, is regarded by Dr. Lee as the centre from which each lateral half of the uterus is supplied; from the hypogastric ganglia, nerves pass in various directions to the os, cervix, body, and fundus, and are distributed extensively to the muscular structure and the internal surface of the uterus. In the course of their ramifications over and in the substance of the uterus, numerous ganglionic enlargements occur. In the virgin uterus, Dr. Lee has specially directed attention to a beautiful ganglion, in front of the hypogastric ganglion, extensively connected with the surrounding nerves, which he has called the Laurentian ganglion, in honour of Mr. Lawrence; and in the gravid organ, Dr. Lee has described numerous sub.peritoneal ganglia and plexuses on the anterior and posterior surfaces of the organ. The se ganglia and plexuses maintain extensive communications with each other and with the hypogastric ganglion below, and the spermatic plexuses and ganglia above." (p. 63 )

According to this description it would be supposed that Dr. Lee was the first to call attention to the "hypogastric ganglion;" whereas Tiedemann and other anatomists, who had carefully dissected the inferior hypogastric plexus, had described the existence of numerous small ganglia united by connecting laminæ, some of them containing ganglionic matter, forming a ganglionic plexus opposite the neck of the uterus. And on Dr. Lee's own showing, such a designation is far more appropriate than one which brings this collection of small ganglia, with their rami of communication, into the category of the large simple ganglia. We are not aware that any satisfactory proof has been given that the so-called "Laurentian ganglion" is any thing else than a portion of the same plexus, with minute collections of ganglionic matter possibly interspersed among

its rami.

It is, however, upon the question of the augmentation of the uterine nerves and ganglia during pregnancy, that the hottest discussion has taken place. Now for ourselves, we have no hesitation in saying that we have not the slightest a priori objection to believe in such an enlargement, with respect at least to the ganglia and fibres of the true sympathetic system; and no one has asserted, so far as we are aware, that the filaments derived from the cerebro-spinal axis undergo any increase. We do not pretend to say what are the functions of these ganglia and nerves. We do not believe them to be independent centres of reflex action; the whole analogy of the sympathetic system is against this view. On the hypothesis of Dr. Radclyffe Hall as to the general functions of that system, their office would be to regulate, through their action on the arterial coats, the afflux of blood to the organ, in accordance with its functional activity. Whatever be their office, it certainly does seem to us anything but unreasonable to suppose that, with the enormous development of the muscular and other structures, the vast increase in the supply of blood, and the elevation of the entire functional activity of this wonderful organ, there should be a necessity for an augmentation of its nervous supply. To assert the contrary, except upon positive evidence, appears to us almost equivalent to asserting that the nerves and ganglia, whose existence is admitted by every one, are of no use whatever. It is maintained, however, by many excellent anatomists, that Dr. Lee's sub-peritoneal nerves and ganglia are not nerves and ganglia at all, but are carved out of the fibrous texture of the uterus; and that no essential difference exists between the nervous supply of the gravid and that of the virgin uterus. We cannot see that