CHARACTERS OF THE OVUM OR EMBRYO.

171

that cases can seldom occur in which the mere presence of a corpus luteum can be taken as a proof of previous impregnation; and they consider the following rules to be deducible from the facts which they have collected: -1. A corpus luteum in its early stage (that is, a large vesicle filled with coagulated blood, having a ruptured orifice, and a thin layer of yellow substance within its walls) affords no proof of impregnation having taken place. 2. From the presence of a corpus luteum, the opening of which is closed, and the cavity reduced or obliterated (only a stellate cicatrix remaining), no conclusion as to pregnancy having existed can be drawn, if the corpus luteum be of small size, and does not contain so much yellow substance as would form a mass the size of a small pea. 3. A similar corpus luteum of larger size than a common pea would furnish strong presumptive evidence, not only of impregnation having taken place, but of pregnancy having existed during several weeks at least; and the evidence would approximate more and more to complete proof, in proportion as the size of the corpus luteum was greater. (Advances in Physiol.' p. 57.)

From this statement, it will be perceived that the difference is only relative and arbitrary, chiefly depending on the size: and as in pregnancy, corpora lutea are found of variable size, while in menstruation they may, under great excitement, attain a large size, it is obvious that no safe inference can be drawn from their presence, irrespective of other signs of impregnation. The terms true and false, therefore, are inappropriate; and serious mistakes may arise by a reception of evidence on this point. The law requires absolute certainty, not merely probability or presumption; and, in the present stage of physiology, the proof falls short of that which is necessary to guide the verdict of a jury. At a trial for attempted abortion, Reg. v. Goodall (Notts Lent Ass. 1846), on examining the body. of a woman on whom the attempt had been made, it was alleged that she was not pregnant: but on inspecting the ovary, a corpus luteum was discovered. This was described as false, apparently because there was no other proof of impregnation. Had an embryo or its membranes been found in the uterus, or had there been some proof of their expulsion, the corpus luteum would probably have been described as true. Meigs says that corpora lutea may vary in size, but in all cases they are real. Physiologically speaking, they do not admit of a division into true and false. (Females and their Diseases,' 1848, p. 43; see 'Edinb. Mon. Jour.' Oct. 1851, p. 305.)

From these considerations, therefore, it appears that the only conclusion to which we can come is, that medical evidence respecting the nature of a corpus luteum in an unknown case, if received by a Court of law at all, should be received with the greatest caution, and only from an obstetric expert of great experience. The old doctrine on this subject, that the presence of such a body on the ovary affords certain and undeniable evidence of impregnation, may be regarded as completely subverted.

Characters of the ovum or embryo to the sixth month.-So far the examination has been confined to the woman, but it is now necessary to describe the characters of the ovum or embryo, and its enveloping membranes at the early stages of pregnancy, since, when these can be procured, they may furnish good medical evidence. If the ovum is expelled within a month after conception, it is scarcely possible to detect it, owing to its small size, and its being enveloped in coagula of blood. Burns examined three wombs, within the first month, where no expulsion had taken place; but even under these favourable circumstances he failed in discovering the ovum. At first the ovum appears merely to consist of vesicular membranous coverings. According to this authority, when first

distinctly seen through its membranes, the embryo is of an oblong form

Fig. 146.

and about a line (the twelfth of an inch) in length. At the sixth week it is slightly curved, resembling, as it floats, a split pea. In the seventh week it is equal in size to a small bee; and by the end of the second month it is bent, and as long as a kidney-bean.

Fig. 146 represents the appearance of the ovum at the end of the first month. a All that is seen here is the loose shaggy surface of the chorion or second membrane (a a). The embryo itself is not seen, as this is enclosed within an inner membrane, called the amnion, which contains a fluid in which the embryo is immersed. Fig. 147 represents the embryo (b) at six weeks, surrounded by its memThe Ovum in its membranes: end of first month. branous coverings, and, on the outside, the chorion (a).

Fig. 148 shows a more advanced stage of the ovum, namely, at about two months after impregnation. The embryo (b) is assuming a fœtal

Fig. 147.

form-the head being downwards, and the place for the eye already indicated: a a, the chorion; c, a portion of the decidua or external membrane.

These engravings are taken from actual specimens in the Museum of Guy's Hospital. They appear much larger than the description above given would lead a reader to suppose, but this is owing to the original specimens being suspended in spirit. By this they acquire an artificial bulk, owing to the flocculent surface of the chorion spreading out to its fullest extent. When removed from the liquid medium, they collapse into a much smaller bulk, and it is thus that they are liable to be carried

The Embryo in its Membranes at

six weeks.

Fig. 148.

away and lost in a discharge of blood. If the embryo cannot be found, some portions of the membranes-especially of the decidua or uterine membrane-may be detected in the uterus.

In reference to the terms here employed, the ovum' signifies the embryo and its membranous coverings; the 'embryo' is the body which is afterwards converted into the foetus; foetus' is the name applied to the embryo after the third or fourth month of gestation.

After the second month, development goes on rapidly: the features are in part well-marked, and the limbs are gradually formed. At the third month, the foetus weighs from one to two ounces: when stretched out it measures about three inches, and the genital organs, although the sex is not then distinguishable, are large in proportion to the rest of the body. The membranes are larger than a

THE EMBRYO.

MOLES.

173

goose's egg. At the fourth month the foetus is from five to six inches long, and weighs from two to three ounces; at the fifth month it measures from six to seven inches, and weighs from five to seven ounces; and at the sixth month, its length is from eight to ten inches, and its weight about a pound. (For the characters of the child beyond this period, see 'INFANTICIDE.') The great difficulty will consist in determining the nature of the supposed ovum or embryo between the second and third month. In making the examination, the substance should be placed in water, and all coagula gently washed away or removed by some blunt instrument. Alcohol may be used as a substitute for water, after the blood has been removed. If the embryo cannot be found, the decidua and chorion, or portions of them, may be recognized: the former by its forming the outer investment, with its smooth internal and rough external or uterine surface; the latter by the villous or shaggy appearance of that portion of it which would have become the placenta. Between the third and fourth month the foetus may be commonly identified without much difficulty. The ovum in many instances escapes first, leaving the decidua behind. This comes away after a time, but it is important to remember that, in some states of the virgin, decidua-like structures are shed from the uterine mucous membrane, which, when examined by the microscope are like the true decidua. Both are constituted of the innermost portion of the uterine mucous membrane, and contain all its elements.

Moles. The true mole is the result of conception, the fœtus of which has died in consequence of the effusion of blood into the decidua and the various membranes, and, should a placenta exist, into its structure. The sac of the amnion has frequently burst, and the ovum has escaped, or it has died and been dissolved by the liquor amnii, which is found turbid. The remains of the umbilical cord are frequently found in the interior of the amnial sac. Nodules are found projecting into the cavity, which are produced by the effusion of blood outside the sac.

Sometimes the

cavity is almost obliterated, the main bulk being made up of effused blood, In the varieties of moles it is not difficult to recognize all the membranes ; the microscope will always enable the examiner to detect the villi of the chorion. Such a mole of course proves conception, but solid bodies are expelled from the uterus which have not this origin, and may occur in the virgin these are called false moles. A clot of blood may become dense, and, losing some of its colouring-matter, exhibit appearances which cannot be distinguished from the true mole, except by the microscope. Polypi may also resemble a mole; but a careful examination would readily show the absence of ovular membranous structures. Sometimes a large exfoliation of the vaginal epithelium may take place, and before its expulsion become condensed, so as to create suspicion. The microscope will, however, show that it consists of tesselated epithelium only. Moles may co-exist with true pregnancy in a case of twins. The symptoms accompanying a mole resemble those of pregnancy; and the appearances produced by its expulsion are not to be distinguished from those attending the abortion of a foetus at an early period of gestation. The only means of distinction would be derived from an examination of the expelled matters. The local injury produced by the expulsion of these bodies on the organs of generation, is by no means as great as that caused by delivery at the full period.

Vesicular mole (Hydatiniform degeneration of the chorion). When by some accident the foetus dies at any time before the complete formation of the placenta, the villi of the chorion, instead of completely dying, grow imperfectly in some parts, serous fluid is effused within, and the part is distended into a globular form. This, occurring frequently in the course of

each villus, gives it a beaded appearance, and the whole mass appears something like a bunch of grapes. The size, however, of each vesicular body varies much in different specimens, and also in different portions of the same specimen, some being only detectable by the microscope, while others are as large as the largest grape. On the largest kinds are generally to be found small villi, undergoing more or less the same process of change. The vesicular growths are attached one to another by delicate threads, the unchanged stem of the villus. This will readily serve to distinguish them from true hydatids ('Obst. Trans.' vol. 1, p. 249), concerning the distinction between which much confusion has existed, and questions have arisen as to whether the vesicular mole can exist or be produced in a virgin. It will be perceived that this latter cannot arise except as a result of impregnation. It is exceedingly rare to find true hydatids in the uterus at all, still more so for them to be discharged through the cavity of the uterus. No authentic account of such a case is on record. But even if it were not so, the slightest examination by the unaided eye would show whether the vesicles were attached to each other as above mentioned, or the smaller enclosed within the larger cysts, or floating without any attachment whatever. The use of the term 'hydatid' does much to perpetuate the error. How long this vesicular mole may remain in utero is uncertain. It may remain more than a year, and possibly many years. The rapidity with which they grow is very great, but this is readily explained by the fact that it is a simultaneous enlargement of myriads of parts. A woman at the third month of pregnancy may be as large as at the seventh month; she may ultimately attain a size exceeding that of the full term. Cases of twin-conception are not uncommon, in which one ovum becomes vesicular, the other going on towards maturity. ('Obst. Trans.' vol. 3, p. 177.) Again, one ovum may become vesicular, while the other is converted into a fleshy mole. In some rare cases a portion only of the chorion is changed into this form of mole, while the proper formation of the placenta may go on in the normal manner.

The question here arises-Can the mature placenta be so converted? Should a portion be left behind in a healthy state, can it assume the vesicular degeneration? From all that is known, this is exceedingly improbable. As a result of observations, it appears that the change only takes place in the villi of the chorion before the formation of a placenta. It is much more probable that, should a woman have no intercourse after labour, but yet expel a true vesicular mole, that it was a twin ovum which was not expelled during labour. In an early stage of pregnancy a decidual covering will always be found more or less complete around this mole, but if the size of the mass is great, then, although present, it will be less observable, being spread over a larger surface. A corpus luteum will also be found, but not so perfectly formed as in normal pregnancy.

The ordinary symptoms of pregnancy accompany this state, although in all forms of mole-pregnancy it is imperfectly marked, or only proceeds to a certain point. (Obst. Record,' vol. 1, p. 21.) It is also to be remembered that the effects of the expulsion of a mole are very similar to those of abortion. These facts may have an important bearing on medico-legal practice. A woman was seized with pains resembling those of labour, and a mass of uterine hydatids was expelled, which was supposed to have been in the uterus about five months. When the woman was examined, thirty-six hours afterwards, there were all the signs of recent delivery about her. The parts of generation presented the usual appearances met with in the expulsion of a foetus: the breasts were enlarged, the areola elevated, of a brown colour, the follicles prominent, and the organs evidently containing milk. The occurrence of this case led

MISTAKES FROM THE CONDITION OF THE UTERUS.

175

Chowne to think that, had the body of an infant been found with marks of violence upon it, concealed in the house where this woman had lived, it would probably have been pronounced to have been her child. A medical man might have strengthened the suspicion of criminality by declaring that there were all the signs of recent delivery about her. It may be observed, however, that in such a case the woman would probably have stated that no child, but some tumour, had come away from her; and a medical man would not be justified in swearing that appearances of delivery absolutely indicated, under all circumstances, that a woman must have been delivered of a child. On the contrary, it is a well-known medical fact, that similar appearances may arise from the expulsion of the various forms of mole. (See a case, 'Med. Times,' Dec. 30, 1848.) Circumstantial evidence would be against her only on the assumption that some person had wilfully concealed or made away with the substantial proofs of her innocence, i.e. the mass which had been expelled. Fischer met with a case in which a woman gave birth secretly to a child, whose death led to a charge of child-murder against her, and two months afterwards she passed a mole or blighted foetus, in reference to which a question of superfotation was raised. (Horn's Vierteljahsschr.' 1866, 2, 22.)

Some of the questions which have been here considered were raised on the trial of Angus for the murder of Miss Burns (Lancaster Ass. 1808). It was alleged that the deceased was pregnant-that the prisoner had administered corrosive sublimate to her to procure abortion, and that this had caused her death. A question arose at the trial relative to the appearances of the uterus as indicative of recent delivery. On examining this organ, it was found considerably enlarged, and on its inner surface was a mark four inches in diameter, plainly discernible, to which apparently a placenta had been attached. The mouth of the uterus was much dilated. Indeed, the appearances were described to be such as might have been expected to be found two hours after the birth of a full-grown foetus. The evidence respecting previous pregnancy was conflicting, and the prisoner was acquitted, because the death of the deceased could not be distinctly traced to any criminal act on his part. The ovaries were not examined until after the trial, when a body considered to be a true corpus luteum was found in one of them; and some eminent authorities agreed that it indicated an advanced stage of pregnancy. (Paris and Fonblanque, 'Med. Jur.' vol. 2, p. 179.) One medical witness appeared for the prisoner, and he contended that the state of the uterus did not justify the medical inference that there had been recent delivery. He assumed that the appearances might have been due to the expulsion of a group of hydatids.' If by the term 'hyatids' he intended the vesicular ovum, he admitted the fact of a conception, and therefore the motive would remain the same. If he intended the true hydatids, then their cyst would have been observable in the nterine wall, and the point of its bursting into the uterine cavity plainly distinguishable; for it is clear that true hydatids would not grow in the uterine cavity itself. The medical defence was for that date ingenious, but at the present time would, for the above reasons, be inadmissible. The contents of the uterus were not produced-a fact which left the case in mystery.