. The

"If the newly-formed lip of the common garden-snail be carefully removed, so as to include a portion of the shelly matter as well as the membrane, and be put into a little water, covered with a thin slip of glass, and examined by transmitted light with a power of 280 linear, it presents the appearance of a thin, yellowcoloured, horny membrane, thickest at its junction with the old lip of the shell, and becoming gradually thinner towards the outer margin. There are an infinite number of minute globular vesicles scattered over the whole of its surface, which vary in diameter from 1-50,000th to 1-3000th of an inch. These vesicular bodies are incipient cytoblasts and cells; for although in the early stage of their growth we cannot discern the nucleus, they may be readily traced through their various stages of development, until in the larger vesicles it may be frequently observed; and the young cells approaching each other are compressed closely together, and become the first superficial layer of cellular structure. completion of the process of the development of the cellular tissue may be best observed in the immediate neighbourhood of the old lips of the shell; and passing thence gradually towards the outer margin of the newly-formed membrane, they may be seen in all their different stages. While the young cells are detached from each other, and retain their globular forms, they are perfectly transparent, the secretion of calcareous or other matters not appearing to have commenced; but we frequently observe in the neighbourhood of the newly-formed stratum small patches of cells congregated together, which are of a deep yellow tinge, and of a semi-opaque appearance, as if they were separate centres of ossification, arising in the same manner that we observe in the production of the calcareous matter in the young cartilages of the bone in the higher classes of the animal kingdom. Amid the great mass of vesicular bodies destined to form the cells for the secretion of the calcareous deposits of the shell, we find other cytoblasts dispersed over all parts of the membrane, which are developed in the form of tesselated cellular structure, by which means the original membrane is very much increased in substance. This production of tesselated cellular structure is more particularly abundant when the calcigerous cells are in their advanced stages of development. If a portion of the newly-formed stratum of shell be removed from the membrane on which it reposes, we observe that the horny structure continues to abound in the vesicles in all their earlier stages of growth; from which it would appear that its office is not confined to the production of the first stratum of calcigerous cells only, but that it is destined to originate the greater part, if not the whole, of the calcigerous cells of the shell; and this appears the more probable, as we may now observe that the membrane has attained a higher stage of organization, minute vascular tissue being frequently observed imbedded aud ramifying amid its structure, and oftentimes projecting from its torn edges. These vessels are very minute, none of those which I have observed exceeding 1-14,000th of an inch in diameter. If the uncovered portion of the membrane nearest to the old lip of the shell be examined with a power of 500 linear, these minute vessels may be seen in the course of formation; presenting the appearance of long ramifying lines of exceedingly minute gelatinous molecules, closely adhering together in a single series, and frequently appearing cylindrical and tubular in one part, while in another they have quite a moniliform appearance. This production of vascular structure by the arrangement of minute molecules or cytoblasts in single series, I have frequently observed in the membranous tissues of the corallida." (p. 6.)

Thus it appears that the hard skeletons which afford support and protection to the soft bodies of animals belonging to the widely-different families among the invertebrated classes, are formed upon a plan essentially the same with that which may be traced in the production of the various kinds of dental structure in the vertebrata. This analogy might in some degree be predicated; when it is considered that the teeth are

produced from the mucous membrane, and may be regarded as parts of the dermo-skeleton, which is developed to the exclusion of the internal or neuro-skeleton, in the lower divisions of the animal kingdom. We have no doubt that the careful study of the history of their development, pursued in connexion one with the other, will lead to some very interesting general results, or rather to an extension of those which have been already attained. Thus it appears from the observations of Mr. Bowerbank, that the tubuli in shell have precisely the same origin as in tooth, being the spaces originally occupied by nuclear particles arranged in rows, and therefore not filled up in the process of calcification. In the larger tubuli these particles are fully developed into cells, which Mr. Bowerbank states that he has frequently met with in cylindrical series; each cell having a distinct nucleus, a transverse diameter of 1-5000th of an inch, and a longitudinal diameter of from 1-3000th to 1-200th of an inch.

The following observation confirms Dr. Carpenter's views, founded upon the structure of the complete shell, in regard to the succession of deposits in each new formation:

"From a careful examination of many new lips in various stages of progressive development, I do not think that the whole of the coagulable lymph of which the new membrane is formed, is exuded from the surface of the animal at one operation, but rather by a series of exudations, each one of which emerges from beneath the terminal margin of the last one; for if the membrane be carefully examined from the line of advance of the newly-formed cells towards its extreme edge, it will be seen that there are several lines of thickened tissue, which correspond in distance and appearance with the lines of growth on the old shell; and this is the more probable, as I have observed in young shells which I have taken from their places of hybernation in November, that the extension of the lip is still going forward, or rather perhaps has been so up to the very period of their retirement for the season." (p. 7.)

We have given a less full account of the researches of Dr. Carpenter and Mr. Bowerbank than of those of Prof. Owen, not because they are less interesting in themselves, but because they have less bearing upon the chief objects of our Journal. None of our readers, we hope, will any longer retain any scepticism with respect to the value of the achromatic microscope as an instrument of research. It may almost be said to furnish the physiologist with a sixth sense, so greatly do its capabilities surpass those of the older instruments.

ART. V.

A Treatise on the Diseases and Special Hygiene of Females. By COLOMBAT DE L'ISERE. Translated from the French, with Additions, by CHARLES D. MEIGS, M.D. &c.-Philadelphia, 1845. 8vo, pp. 720.

In the year 1838 M. Colombat de l'Isère published two volumes of a treatise on the Diseases of Women, and completed it by the publication of a third volume in 1842. He gives an account in this work of all the diseases of the impregnated and unimpregnated conditions, as well as of the puerperal state. Unfortunately, however, he possessed few qualifications, besides industry, for the performance of his difficult undertaking. His

work is a mere compilation, often extremely ill-executed, and showing but little critical knowledge; the author's aim appearing to be that of quoting as large a number of writers as possible, while he pays but little regard to the comparative importance of their opinions.

Such being the character of this book, we cannot but feel surprised that a gentleman of Dr. Meigs's great experience should have thought it worth. his while to engage in the wearisome occupation of translating it into our own language. He would seem, indeed, to have found it an irksome labour, if we may judge from the small amount of pains that he has devoted to the performance of his self-imposed task. We strongly suspect that Dr. Meigs has intrusted the main drudgery of translating to some inferior hand, thinking that the supervision of the proofs and the addition of notes to the text, would sufficiently justify the announcement of his name on the titlepage as translator.

To show our readers how well Dr. Meigs is qualified to write on the subjects treated of in this volume, we will here notice some of the principal additions made by him to it—more especially such as are of a practical nature. We are sure that no one who peruses these additions will fail to express his regret that Dr. Meigs did not give us an original work of his own instead of a careless version of M. Colombat's.

Epoch of puberty. To the chapter on the "phenomena of puberty," Dr. Meigs appends a note on the epoch of puberty and the critical age of the females of the republic of Venezuela, founded upon the researches of Dr. Vargas of Caraccas. From these it appears that in 70 per cent. menstruation occurs from the age of 13 to 15 years, while the most common period for the cessation of menstruation is from the age of 45 to 48 years. Precocious menstruation is more common in the white than in the negro

race.

Menstruation. We have been much surprised to read the following statement at p. 33. "It is well known, that in a great metropolis like Paris or Philadelphia, there exist multitudes of women who do not take the least precaution to prevent the blood of the menses from soaking through their clothes, and exposing their condition to the public eye in the street or in the market-place!" From a very extensive acquaintance with the habits of the poorer females of this metropolis (London), we are convinced that every precaution is taken by them to prevent such an indecent exhibition.

To the chapter on the cessation of the menses, Dr. Meigs adds a tabular statement, showing the age at which this function ceased in 183 females. His observations agree with those of M. Brierre de Boismont.

Anatomy of the vagina. At p. 48 he directs special attention to an omission in the original text in the anatomical description of the vagina, viz. that while the posterior and part of the lateral walls are inserted into the soft and distensible parts, as the perineum, the anterior and part of the lateral walls are firmly attached to the pubic arch; so that in labour, when the vagina becomes lacerated, it is the anterior or antero-lateral surfaces which give way, these not yielding so readily by reason of their firm attachment. In remarking upon the distensibility of the vagina, Dr. Meigs makes some judicious remarks upon the necessity of remembering this quality of it when the tampon is employed to arrest hemorrhage in

early abortion or menorrhagia. The tampon he recommends "consists of portions of linen torn into squares of three or four inches, of which the pieces are successively introduced until the cavity is quite filled."

Enlarged clitoris. At p. 83, Dr. Meigs relates a case of enlarged clitoris, which was under the care of Dr. Norris, of the Pennsylvania Hospital. It occurred in a patient 36 years of age, had existed fourteen years, and commenced after she had received a blow on the part. It gave to the hand the sensation of indistinct fluctuation, and was not painful even when smartly compressed.

A common lancet introduced into the base of the tumour gave exit to about twenty-two ounces of a thick, blackish fluid, of the consistence of tar, perfectly inodorous, and very similar to retained catamenial fluid. After relating this case, the Doctor remarks, "so far as my knowledge extends, there is no example of blood detained for months and years in cavities, without undergoing decomposition, except when it is detained within. the generative tissues."

Malformations of the vagina. At p. 91, he relates a singular case. The patient was in labour, and considerable delay and difficulty were experienced by the division of the vagina into two lateral halves by a septum which extended from the external orifice or os magnum to near the uterine extremity of the canal; the head of the child forced into the right half compressed the other against the left side of the pelvis. Dr. Meigs delivered the infant alive, "without accident or any untoward result." After the patient's recovery an accurate examination was made, when it was found that the septum had not given way during the distension of the right canal.

At pp. 95-99, some cases of congenital narrowness of the vagina are related, and in the remarks appended to these cases the translator takes occasion to recommend "simple graduated dilatation," and strengthens his recommendation by the advantages which follow gentle dilatation of the urethra in strictures of that canal; by the usual effects of the pains of labour on the cervix uteri, vagina and perineum, which he has "familiarly" noticed; by the gradual distension which the female urethra and rectum allow, the former permitting the index-finger, the latter the hand to be introduced. He strongly advises against the use of cutting instruments in such cases.

At p. 101 he records an interesting case of occlusion of the vagina after parturition, without any assignable cause. Fortunately Dr. Meigs was consulted before the cohesion which had taken place between the anterior and posterior wall of the vagina was very firm, and he therefore was enabled to separate them with the bulb of a probe, the patient losing not more than two or three drachms of blood. A second case is described, taken from the 'Philadelphia Practice of Medicine.'

Absence of the womb. To M. Colombat's chapter on this subject Dr. Meigs appends a note recommending that in cases of protracted emansio mensium, marriage should be postponed until after the menses have appeared, or until a competent inquiry has been made as to the fitness of the female to enter into the marriage compact, illustrating his observations by the recital of the case of a "handsome woman" by whom he was consulted, and who, although 22 years of age, and married upwards of two years, had never

menstruated. The mammae were well developed, the pudendum amply supplied with hair, in fact there was perfect development of the sexual system, but total absence of menstruation. For two years and upwards the husband had failed in his attempts to accomplish sexual congress, when at length Dr. Meigs was consulted. Careful investigation discovered the vagina to be a cul-de-sac, scarcely two inches in length, and the uterus to be wanting. A similar case has lately fallen under our notice. Such cases, however, must be of rare occurrence, for when proceedings were instituted to obtain a nullity of marriage, no precedent was discovered in the records of the court.

Prolapsus. Dr. Meigs is of opinion that prolapsus uteri in many instances is occasioned by the floor of the pelvis, or tissues of the perineum losing their full power and energy, and especially by the weakness and loss of power of the levatores ani. He differs from M. Colombat in the opinion that "intense peritonitis" is induced as one of the complications of prolapsus, but regards it as simulated peritonitis, the diagnosis of which he admits may be very difficult.

Polypus. Dr. Meigs wisely cautions his readers against placing implicit confidence in a statement of Colombat when speaking of the diagnosis of polypus uteri-viz., that "polypus uteri is irreducible, and any attempt at reduction causes insufferable pain, while, on the contrary, prolapsus uteri is easily reducible, and its reduction gives great relief to the patient." Dr. Meigs most properly says we sometimes meet with examples of polypus uteri which are occasionally accessible, and at other times retire beyond the reach of the finger; for instance a pediculated polypus may be attached to the fundus, and may be forced partially through the os uteri by contraction of the parietes, and when such contraction ceases it will be again drawn into the cavity. (p. 126.) A case in point is at the present time under our

care.

Use of the pessary. At pp. 136, 140, and 150, Dr. Meigs makes some judicious remarks on the pessary and its employment. We fully agree with him that "great abuses are to be met with in the prescription and use of this instrument," while "many persons are restored to health, or procure a tolerable state of health by its use.' He urges that every case of prolapsus or procidentia uteri should be regarded as an affection of the vagina, and that the indication of cure should be "the restoration of this canal." He strongly advises against treating prolapsus by long continued rest in the horizontal posture, as it is apt to exhaust the "muscular force of the patient," "weaken the levatores ani," and "relax the perineum,' which becomes nearly horizontal, or quite even with the tubera ischii; and, on the contrary, he recommends "exercise, air, and light, a nutritious diet, wine, and malt liquor," believing that in proportion as the general health improves, the local disorder will gradually lessen and finally disappear. When a pessary is indicated Dr. Meigs prefers the globular form of instrument, as it cannot become displaced by turning on its axis, and one made of silver, or silver washed with gold, of about two inches and a quarter in diameter. He advises "some time" to be taken in the introduction; for if it enter "too readily, or if it be not properly adjusted," it will be expelled at the first bearing down in defecation or in evacuating the urine. It is to be placed in the vagina beyond the constrictor muscle.