It is uncertain at what time the ovum enters the uterus. Dr Haighton could not detect it in the ute rus ol the rabbit earlier than from the fourth to the sixth day. Now, in that animal the period of utero gestation is only 30 days ; from analogy, which doubt less is not to be held as proof, one would not expect to find it early in women, who go so mush longer. Some microscopic observers have supposed that they saw the embryo eight days after conception ; but, be this as it may, it cannot be detected with the naked eye for much longer. It is not probable that the ovum can be seen in the uterus until nearly three weeks after conception. In an instance where the conception could not be less than five weeks, the membranes were of the size of a small chesnut, and the foetus scarcely so large as an ant. In the sixth week it is curved, forming a bulk like a split pea. In the seventh as large as a bee. In the eighth, about the size of an or dinary bean. At first the embryo consists merely of two oval bodies joined together, which are the rudi ments of the head and trunk ; then the extremities sprout out like buds, and the different organs become gradually developed. At the full time a male child measures about twenty inches, and the average weight is seven pounds.
At first, from the increased weight, the uterus sub sides in the pelvis, at the same time that the os uteri becomes more circular, instead of transverse. as for merly. In course of time, however, it becomes so large that it can no longer remain sunk in this situa tion, but rises above the brim of the pelvis. The time at which this happens must depend to a certain degree on the capacity ol the pelvis, and the enlargement of the uterus It usually happens in the end of the fourth month, that is, alter 16 weeks from conception, but it may be earlier, and is often somewhat later. This elevation takes place in general rather suddenly, and in many cases the sensation occasioned by the ris ing of the uterus is very well marked, and sometimes accompanied with fainting, or hysterical symptoms. This is confounded by many with the motion of the child itself, which is felt about this time, and the per son is said now to quicken. It is quite absurd to sup pose, that before this the child is not alive, and does not move. The motions are now felt, because the child is stronger and larger, compared to the quantity of liquor amnii, and the uterus is in a more sensible situation. Lawyers, however, who are in general bad physiologists, have decided that it is murder to procure abortion after the time of quickening, but a minor of fence to do so earlier. If any doubts have existed re specting the existence of pregnancy, they are at this pe riod cleared up ; for the patient herself is sensible of the motion, and the accoucheur, by examination per va ginanz, feels the uterus to be heavy, and when vressed up with the finger, there is perceived the mortvement de ballotement : and by. gently striking the under part, of
the uterus once or twice, the foetus is perceived dis tinctly to move or flutter within.
It requires nine months to bring the human foetus to perfection, and experience teaches many women, from particular feelings, how to judge pretty accurate ly with regard to the time when they are to be con fined. When there is no particular circumstance to guide them, the general way is to calculate forty two weeks from the last period of menstruation, forty weeks being the term of gestation. This determines within a fortnight, and farther assistance is derived from attending to the time of quickening. Many bring forth before the full time, but it is rare to go beyond the ordinary time ; but it is certainly possible to do so.
Children born in and after the seventh month may live, but the nearer they approach to perfection, the more likely are they to thrive. If they have no hair nor nails, and the skin be not red about the palms of the hands, breast, and scrotum, and if they can neither cry nor suck, there is no chance of their living. In stances, however, have occurred, where children in the sixth month have been kept alive, by being fed and kept warm.
Of the Signs of Pregnancy Although some women very early begin to have complaints, or to experience certain sensations which apprize them of conception having taken place, yet in general the first indication of pregnancy is the interruption of the menstrual action. It has been a question for discussion amongst medical men, whether the menses have ever continued to appear regularly during pregnancy, and, notwithstanding the different instances which have been brought forward to the au thor. he is still convinced that the two conditions are so incompatible with each other, that regular menstru ation is inconsistent with pregnancy. It is placed be yond all doubt, that many women have had periodical discharges during part or the whole of pregnancy ; but these, from the attendant circumstances, are rather to be viewed as hemorrhages than as a continuation of the natural secretion. Yet Baudeloque, Chambon, and other respectable men, have told us of instances, where women did not menstruate except during gestation.* The breasts very early sympathise with the uterus. It is not unusual for them at first to become a little smaller, but by the third month there is an evident enlargement, and the nipple presently becomes sur rounded with a brown areola. The augmentation of size is slower of taking place in those who are delicate, or who have sanguineous evacuations from the uterus during the early months of pregnancy. A serous or milky fluid also is secreted, and either flows from the nipples, or can be pressed out.