Cruveilhier* relates the particulars of a case in which the effect of disease of the placenta in producing atrophy of the fcetus was strikingly shewn in twins at the sixth month, one of whom possessed the full development and characters belonging to that period, but the other, whose portion of the joined plaeentw was thin and un vascular, presented a size corresponding to not more than three months, as shewn in 148.
In another case, formerly under the writer's care, the fcetus expelled at the ninth month had only grown during the first threel Such cases as the above possess an interest and a demand on our attention of a very im portant kind, as illustrative of the necessity for carefully examining into the state of the foetal appendages as to their healthy condition or otherwise, before we venture to pronounce an opinion on the time that has elapsed since con ception, merely from the size or general ap pearance of an ovum or fcetus shewn to us ; for here we have, in one instance, an ovum, the size of which and that of the contained fetus, would indicate a period of two months' preg nancy only, whereas five months had really elapsed from the time of conception, for the parties had not cohabited since the time of the threatened abortion; and in the other case an ovum of three months' growth is expelled nine months after conception. Now, in either case, had the husband happened to die, or to have gone from home, shortly after the time of con ception, and the accident to have occurred in the same way, the female might have sustained, though most unjustly, a severe injury to her reputation.
Hcrnir.—Hernia is a very frequent occur rence in the fcetus, especially at the umbilicus, where, in the earlier periods of foetal life, the anterior wall of the abdomen is deficient and the intestines covered by the expansion of the sheath of the cord, into which they project, in some instances considerably; of this there are several specimens in the writer's museum ; not 'infrequently this natural deficiency remains up to the time of birth, and congenital umbi lical hernia is found in the child.
In the simpler forms of this affection the her nial sac contains intestine only, but in other instances which have occurred to the writer, some of which also he has preserved, it con tains the liver and stomach in addition to almost the whole tract of intestines : such ag gravated forms are in general connected with other malformations, such as spina bifida, spon taneous amputation, &c. which combinations
arc noticed under their respective heads in the present article. In a specimen which occurred recently in the writer's practice the liver was protruded into the sheath of the cord, but all the rest of the abdominal viscera were con tained in the natural cavity. Inguinal hernia sometimes exists before birth, but is rare. Her nia eerebri is noticed elsewhere.
Diaphragmatic hernia, or protrusion of the intestines through the diaphragm into the ca vity of the thorax is of rather rare occurrence, or perhaps, more _properly speaking, is less frequently observed, because it presents no external physical alteration of form to attract attention.
Like umbilical hernia in the fcetus, it is the result of incomplete developement, because in the earlier periods of &etal life the diaphragm does not exist, and the thoracic and abdominal cavities are one ; and as the muscle afterwards becomes developed from its circumference to wards the centre, there occurs occasionally an arrest of formation, and in consequence an aperture is left, through which the intestines and other abdominal viscera, as they increase in size, pass into the cavity of the thorax, dis placing the heart and lungs, the latter of which organs are thereby frequently so pressed upon that their developement is prevented, and there is sometimes but a very small portion of them discoverable, especially of the one at the side where the hernia principally exists; which, in a vast majority of the cases which have been met with, has been the left, and then the heart has been pushed over to the right side, where its pulsations in children born alive have some times given the first intimation of the existence of the lesion under consideration. In general, children so affected in utero have been either still-born, or have died very soon after birth, a consequence which it appears reasonable to suppose results from the state of the lungs. But in some instances the children have sur vived under such circumstances. Becker saw one that lived five years; and in a case re corded by Diemerbroeck, where the diaphragm was entirely absent, the child lived seven years, annoyed only with a frequent cough. Itiviere and J. L. Petit mention instances of life much more,prolonged, in the same condition.