Lactation in the greater number of women prevents conception for a time, generally for from six months to a year, but in other women seems to have no effect.
It is very obvious that the state of mind of the female has very little to do with conception, as it is well known that conception • occurs where there is no love, no desire, in pain, in sleep, and in the state of insensibility; and it is equally well established that sexual feelings are not necessary for the occurrence of concep tion, although it is possible that they may in some instances indirectly assist. It is worthy of remark that there are examples of individuals of opposite sex whose marriage has been barren, both having had children with others.
Signs of recent conception in woman.—Before concluding the subject of the changes in the in ternal generative organs of the female which follow fruitful sexual union, let us recapitulate shortly the principal circumstances which may be considered as evidence of conception having recently occurred in the human female.
In the first place, there is no one point of evidence which is conclusive in the early period of gestation excepting the finding the ovum or fetus; and here we must be on our guard against confounding the mole, or such pro ductions which occur in the virgin, with the true ovum. The other signs of conception afford little satisfactory evidence singly, though they are important when several are conjoined.
The signs of conception may be distin guished into those which in some measure affect the whole system, which may be called constitutional or general, and those which are more strictly local, or affect principally the generative organs.
The more general signs are 1. The interruption of the menstrual flow at the usual period when there is no other obvious cause for it.
1. Fulness and enlargement of the breasts, and vascularity of the areola surrounding the nipple.
3. Derangement of the functions of the stomach ; frequent nausea and even vomiting, especially in the morning, with depraved ap petite, headache, &c.
4. An accelerated pulse, and some febrile symptoms.
The local signs are 1. A slight enlargement and increased vas cularity of the uterus.
2. The closure of the mouth and cervix by a peculiar viscid secretion.
3. The existence of the commencing decidua or substance from which that membrane is formed.
4. A vascular condition of the ovary, with very much enlarged vesicles, a ruptured vesicle or corpus luteum, and an increased vascularity or enlargement of the Fallopian tubes.
Such local signs can only be obtained by the examination of the body after death. When the greater number of them co-exist and have been attended with the more general con stitutional signs, there is strong presumptive evidence of conception having occurred. But nothing short of the appearance of the child either passed in abortion or found after death would entitle us to conclude with certainty that conception had taken place, until those more obvious signs, which are found after the period of quickening, make their appear ance.
§ 2. As regards the male organs.
Fecandation.—In continuing the detail of the phenomena which accompany or succeed to fruitful sexual union, we come next to the con sideration of the process of fecundation. We shall begin this subject by a sketch of the nature and properties of the product of the male generative organs, viz. the seminal or spermatic fluid, and afterwards state the more important facts which appear to throw light upon the mechanism of the remarkable in fluence exerted by that fluid on the ovulum produced by the female.
Properties of the seminal fluid.—The se minal product of most animals is a whitish fluid, which to the naked eye appears homo geneous or nearly so ; but in the human spe cies and some of the higher animals, the seminal fluid or substance, ejaculated from the male organs during sexual union, con sists of two parts of different consistence and appearance ; in the human species, the one being of a pale milky colour and more fluid, the other clearer, semi-transparent, and more of the consistence of thick mucilage.