Corpus Luteum.-Importance was attached at one time to the presence or absence of a corpus luteum, or the yellow body developed through modification of the lining membrane and contents of the Graafian follicle from which an ovum had escaped, as proving or disproving pregnancy. A foetus is not unfrequently found, however, in the uterus where there is no trace of a corpus luteum in either ovary; and, on the other hand, a well-developed corpus luteum, undistinguishable from that of pregnancy, may be found in the ovary of a woman who had never been pregnant, and even in that of a virgin. The presence or absence of a corpus luteum cannot then be regarded as having any importance in medico-legal cases involving questions of pregnancy.

Responsibility of Mistaken Diagnosis.-As the so-called "certain signs" of pregnancy, with the exception of the pulsation of the foetal heart, are only relatively more certain than the uncertain signs, the medical examiner should be extremely cautious, under any circumstances, in stating positively that a woman is pregnant, and especially if she be unmarried and of previously good character. On more than one occasion has the reputation of a virtuous woman been ruined and the happiness of her family destroyed by a too confident examiner mistaking a condition of disease for that of pregnancy. When once the virtue of an innocent woman has been thus impugned, and her previously good character taken away, though in time the injustice of the charge will surely be proved, reparation will come too late, and no atonement can be made for the wrong done the woman or the misery inflicted upon her family. Apart from the injury due to a mistake in diagnosis under such circumstances, the examiner should remember that as

FIG. 1. Ovary of woman two days after menstruation, showing earliest stages of transformation of a ruptured and bloody Graafian follicle into a corpus luteum.

FIG. 2. Ovary of woman nine days after menstruation: the dark spot is the cicatrice; the surrounding yellow circle is the corpus luteum shining through the transparent tissue. FIG. 3.-Ovary of woman at term of pregnancy, showing corpus luteum with firm white central clot.

FIG. 4.-Ovary of woman twenty days after menstruation; besides large fresh corpus luteum are seen two smaller old ones, and Graafian follicles of different sizes (DALTON).

the best obstetricians may be mistaken, his own reputation as a medical expert may be at stake.

Cases of supposed pregnancy differ in one respect from other cases demanding the attention of the medical jurist -namely, there is no necessity that a positive opinion should be expressed upon the subject. No harm can result from the medical examiner refusing to state positively whether a woman is pregnant or not. It is far better to give the woman, if unmarried and of good character, the benefit of the doubt, than positively commit yourself to the expression of an erroneous opinion in the case. It should always be remembered that nature will soon answer so positively the question whether a woman is or is not pregnant that there will be no necessity of the examiner weighing the relative value of the uncertain and certain signs of pregnancy.

Duration of Pregnancy.—The determination of the duration of pregnancy under certain circumstances, as in cases involving questions of legitimacy and inheritance, may become a matter, medico-legally, of the greatest importance. It may as appropriately be mentioned here as elsewhere that the ordinary period of gestation is nine calendar months (270 to 276 days), or ten lunar months (280 days), the physiological presumption being that parturition occurs at the period which would correspond to the tenth menstrual period since the last one. The greatest difference of opinion prevails, however, as to what shall constitute the longest and shortest possible periods of gestation. The difference of opinion in this respect depends to a great extent upon our ignorance as to the exact moment of conception. As conception may take place at any moment of the period intervening between the menses, it is evident that there may be a difference on this account alone of twenty-eight

days in the period of gestation, according as conception was supposed to have taken place immediately before the period at which the menses would have occurred had not conception taken place, or immediately after the last menses which actually did occur. Further, the duration of pregnancy varies very much in different women on account of personal idiosyncrasies, as well as on account of other causes not understood. Obstetricians have claimed that mature children have been born as early as from 210 to 217 days,' and as late as from 313, even to 325, days after sexual intercourse, there being a difference between these very exceptional extremes of as much as 96 days. Cases are not rare, however, in which the difference in the duration of gestation in cases of mature children amounts to as much as 44 days, the two extremes of gestation being 249 and 293 days respectively. It should be mentioned in this connection that while a child born after a period of protracted gestation is neither larger nor better developed than one born after the average period, a child born only seven months after sexual intercourse is always immature and imperfect-readily distinguishable from one born after the average period. It is for this

reason that the statement that a mature child is born seven months after sexual intercourse must be regarded as most exceptional. In tropical countries women become pregnant at a much earlier age than in temperate climes. Thus, in India and Abyssinia it is no uncommon occurrence for girls of only eleven and twelve years of age to bear children. Pregnancy has been known to occur, however, even in children of only eight and nine years of age. On the other

2

Beck: op. cit., vol. i. p. 599.

Montgomery: Signs and Symptoms of Pregnancy, second edition, London, 1856, pp. 523, 546.