catamenial flow, and not just antecedently to its expected return. The table is highly interesting, in the relations for which I would use it, showing, as it does fully, that there is a considerable latitude in the duration of gestation.

"Mr. Gaskoin communicated an account of suspended animation, during four years, at least, in a specimen of helix lactea, now living in his possession. A remarkable feature in this case is the fact that utero-gestation was suspended, and resumed its process with the resumption of vitality."-Athenæum, Nov. 30, 1850.

Computation of Term.—The ordinary term of a gestation is attained in about two hundred and eighty days, and it is customary among medical men to assign the two hundred and eightieth as the day on which the child may be expected to be born. In making the computation for my patients, my own habit has been, to inquire as to the day and date of the disappearance of the last menstrua; to commence the series on the day following the disappearance, and add two hundred and seventy-nine days to it. This mode has answered my purpose well enough, but it is clear that it would not answer for the calculation of term, in the case of a religious Jewess.

That experienced practitioner, and most judicious author, Professor Nægèle, of Heidelberg, in his Lehrbuch der Geburtshülfe, 8vo., 1842, in a remark at the foot of page 82, gives the following method of computing term. Let the woman reckon three months back from the day when her menses ceased, and to the said three months let her add seven days. The day thus found is the one on which she ought to expect her confinement. If, for example, she had her courses last on the 10th of June, let her reckon backward three months, to March 10th, to which she should add seven days, which would bring the calculation to the 17th of March. This would be the day, to wit: March 17th, on which the woman ought to expect her lying-in. Such is the method of calculation recommended by Dr. Nægèle, and it must be admitted that, as no man in Europe enjoys a more enviable reputation as a teacher and practitioner in our art, one might feel safe in following his example in the practice of it. Still, I cannot perceive why the seven days should be added to the three months, or, rather, to the whole term, since the Professor gives no reason for us to suppose that the ovulum is not both mature and ready for fecundation as soon as the catamenial flow has ceased, and the genitalia have recovered their fitness for the congress of the sexes. As I have had no reason hitherto to find fault with my own method, I shall continue to compute from the day of cessation; so that, if my patient should inform me she saw

the last stain on August 27th, I should reckon backwards to July 27th, June 27th, and May 27th, which day I should indicate as the one on which the labor might be expected to commence, and not June 3d. My opinions as to the connection of the menstrua with the acts of ovulation are so settled, that I do not expect they shall be changed hereafter. Still, those opinions do not prevent me from supposing it sometimes possible for an ovulum to become mature, and even to escape from its ovisac, without exciting the usual mensual molimen—and even, also, that this escape might take place just before the period for the catamenial return, or at any other period. Under such fortuitous circumstances, a fecundation might be possible just before the period of return; and if so, the calculations as to term would be liable to give rise to a disappointment. In general, however, one may venture to rely that a general rule will hold good-while no great surprise ought to arise when an exceptional instance happens to fall under notice.

Changes in the Womb.-The form of the womb changes with the progress of pregnancy. The vaginal cervix grows shorter, and at length wholly loses its cylindrical, or tubular shape, leaving at the upper end of the vagina a convex or conoidal protuberance with a dimple in its apex, which is the os tincæ of the womb-at-term.

As the ovum expands, it carries the uterus along with it, at first making use of the cavity of the fundus and body of the organ, and only distending the upper part of the cervix in the first months of pregnancy; so that, if an examination should be made of a woman three months pregnant, the cylindrical cervix uteri would be found to have undergone very little shortening.

The cervix certainly becomes fuller and larger, at a very early period of pregnancy, and presents, in this respect, a sensible difference from its unimpregnated state. At the close of pregnancy, the tubular cervix uteri seems to have wholly disappeared, and the womb, instead of exhibiting a straight or cylindrical neck, is become conoidal, the os tincæ being at the lowest end. No decided change in the length of the cylindrical part is discovered by the Touch until after the fifth month, or, according to certain authorities, the seventh month. From that period it grows daily shorter, until the last days of gestation, when the cylinder is not discovered at all. A pregnant woman, therefore, in whom it has wholly disappeared, is said to be ready to commence the process of labor. The attack of labor pains may begin very soon after the disappearance of the cylinder of the cervix, or it may be deferred for several days, from causes which are not understood.

In all instances that have fallen under my notice, the thickness of the walls of the womb, when at term, has been rather less than in the non-gravid organ. The tissue is much looser and easier to cut, and yields to any distending force far more readily in the gravid, than in the non-gravid state. It is incomparably more vascular, so that, in the last weeks of gestation, it may be compared to a purse or network of blood vessels, with abundance of loose cellular tissue, and muscular fibres interspersed. I have sometimes compared it to a vast hollow aneurism by anastomosis, in order to express an idea of the abundant vascularity with which it is now provided, and by the agency of which it is enabled to fulfil the wants of the foetus as to aëration and nutritive absorption. The uterine arteries and veins which reach the womb near its lower extremity, inosculate freely with the ovarian or spermatic vessels, that enter its texture betwixt the folds of the broad ligaments, to supply the ovaria, the Fallopian tubes, and upper portions of the womb.

Smellie, vol. ii. p. 19, says that he had opportunities, in 1747 and 1748, of opening the bodies of two women who died at the full term of utero-gestation. The membranes were unruptured. They were each about a quarter of an inch thick. The same was the case with another specimen in his possession, which was in the eighth month of pregnancy. He had seen several others, in which the woman died soon after delivery, the womb not being much contracted, when the thickness of the walls was about the same as the above. But where the death did not occur for several days after delivery, and the womb was contracted, he found its parietes from one to two inches thick.

In the cases that I have seen of autopsy of the pregnant woman, I have always found the head of the child to present at the os uteri. I cannot agree with the opinion of M. Paul Dubois that the child is instinctively compelled to turn its head downwards, for I can neither discover any such instinct in the unborn foetus, nor power to obey it if it should exist. M. Dubois's paper on this subject in the Transactions of the Royal Academy of Medicine is, however, well worthy of a perusal.

Uterine Muscles.-With regard to the muscular structure of the womb, I shall remark that no person who has witnessed the exercise of its muscles in labor, can doubt of their immense power; particularly should he have felt its force while the hand has been compressed by it, in turning a child in utero. Some years since, a gentleman of this city found himself obliged to introduce his hand completely into the womb, in order to extract a retained placenta. While the hand was employed in separating the afterbirth from the uterus, the os uteri closed upon his wrist with such force as to give him very severe pain, and he found it impossible to withdraw the hand, which was com pletely fastened by the contraction. After various unsuccessful attempts to extricate himself from such an unheard-of difficulty, he sent for a Bleeder, and, after causing a large quantity of blood to be drawn from the lady's arm, the spasm of the cervix ceased, upon which he was liberated from an imprisonment of two hours. His wrist was marked, as if a cord had been strongly bound round it; the red traces of which impression were visible even the next day.

The operation of turning the child in a powerful womb, from which the waters have been entirely drained, not unfrequently produces from

Fig. 68.

pressure, a degree of numbness so great as to make it necessary to withdraw the one, and introduce the other hand-the sensibility and motion of the first one being wholly suspended; the resistance to be overcome in the expulsion of a grown foetus requires a muscular force which cannot be exactly estimated, and must, therefore, be immense.

Different writers describe the arrangement of the muscular fibres of the uterus in different manners. The very discrepancies of these authors ought to convince us that their arrangement is not yet understood;

and, indeed, it is of no great consequence, in a practical view, that it should be demonstrated. It is enough to know that the fibres are so arranged as to tend, by their combined contractions, to reduce the uterus back from the gravid size to that of the unimpregnated organ. When their contraction is co-ordinate, the fundus tends to approach the os tincæ, and the sides tend to approach each other. Whatever is contained within the cavity of the organ is, under these circumstances, expelled therefrom.

It should be always understood that, in speaking of the muscular structure of the womb, we speak of the gravid womb only, in which the arrangement and condition of those fibres are perhaps very dif ferent from those of the virgin or the non-gravid organ. Fig. 68 is a representation of their arrangements, proposed by M. Chailly, which differs from the very beautiful drawing of a dissection of them, that is given in Dr. Moreau's Atlas. Both of them are unlike Madame Boivin's figure-and I have no doubt that every successive representation will differ from those that do, or may, precede it. My own attempts to extricate the tangled maze of muscular fibres leave me convinced that the only anatomy of them to be depended on, is the Transcendent anatomy-or that which is performed by the reason and not by the scalpel. He who has felt the womb contract upon his hand in a Cæsarean operation, or in repositing an inverted uterus after labor, or in extracting the placenta in hour-glass contraction, or in turning the child long after the waters are gone off, will have a better conception of the muscularity and of the arrangement and distribution of the muscles than he who trusts to the dissecting knife alone.

The action of the muscles of the womb ought, if normal, to be perfectly co-ordinate, all parts acting together, and at the same time. It is, however, true that, in the state of contraction, all the parts do not always begin and cease to act at the same moment.

Labor does not always proceed with regularity. The muscular power of the womb is occasionally found to be morbidly exercised. Those fibres that tend to bring the fundus near the os tincæ, sometimes fail to act, or act imperfectly; while those that tend to approximate the sides of the womb act with such force as to compress the body of the foetus, and, instead of expelling, rather confine and detain it within the cavity. We frequently observe women to suffer under the most violent uterine pains, which nevertheless do not move the child downwards in the least degree; such pains should be suppressed, if possible, in order to admit of the co-ordinate and regular operation of all the fibres being restored, by temporary cessation or repose. It