IV. CHANGES CONSEQUENT ON FRUITFUL SEXUAL UNION.
1. As regards the female chiefly. Concep tion.—The consequence of fruitfu•sexual union in man and quadrupeds is the dislodgement of one of the ova contained in the ovarium, and the fecundation of this ovum in somepart of its passage from the ovarium, where it is formed, to the uterus, in which the foetus is developed from it.
In now proceeding to treat of the mode in which these further steps of the generative pro cess are brought about, the following subjects present themselves for our consideration. 1st. 'What changes are operated in the internal female organs after fruitful sexual union, and by what means are the ova dislodged from the ovary ? 2d. What changes do the ovaries or their vesicles undergo after the discharge of any of the ova ? 3d. What happens to the ovum from the time of its discharge from the ovary until the commencement of the development of the fatus ? 4th. In what part of the female ge nerative system is the change of fecundation effected by the agency of the seminal fluid upon the germinal part of the egg? and lastly, In what does the change of fecundation consist, or upon what properties of the seminal fluid may it be supposed to depend ? These topics comprehend the history of the functions of the male and female internal gene rative organs, in so far as they relate to the pro cesses of conception and fecundation ; under which two heads, as has been already men tioned, it is our intention to bring the remainder of the facts respecting generation which come within the limits of the present article. We shall begin with those facts relating chiefly to the female, or conception.
The immediate consequence of sexual union upon the female internal generative organs is their great excitement, and a turgescence pro duced by an accumulation of blood in their vessels. When sexual union proves productive, this turgescence lasts for some time after it has taken place, so that in animals opened at this time, the ovaries, Fallopian tubes, and uterus are found to be of a much deeper red colour, and more vascular than in their natural state. In the female Rabbit, for example, opened soon after coition, the internal organs are nearly black from sanguineous congestion.
There also occurs in some of these parts a change of position in regard to one another, which is connected with the discharge of ova from the ovarian vesicles. The fimbriated ex tremities of the Fallopian tubes are turned to wards the ovaries on each side, and embrace these organs closely, so that the infundibular opening is applied against the ovary, and must of necessity receive the contents of the Graafian vesicle when it bursts. In some animals the ovary is inclosed in a sac along with the infun dibulum by a reduplication of the peritoneum, so that the ovary is kept always to a certain extent within the infundibulum ; but in other animals in which the connection between these parts is not of this permanent kind, there is all equally firm union of them after copulation. In regard to the means by which this approxi mation and union of the fimbrite and ovaries are brought about, it may he stated, that in some animals the action seems to be somewhat of a muscular kind ; for there are strong fibres, having all the appearance of muscular fibres, which pass from the ovary towards the fimbri ated portion of the Fallopian tube ; and in these animals, as well as in others even, in which the muscular fibres are less obvious, irri table contraction may be supposed to be a means of bringing the parts nearer to one another. The observations of Ilartssker and !faller, however, would appear to shew that the vascular turgescence which follows co pulation, amounting to a state approaching to erection, may also contribute to give rise to the change of position now under consi deration, for they found by repeated trials that the forcible injection of fluids into the bloodvessels of the generative organs in the human dead body caused the approxi mation of the fimbrite and ovaries. But, although it may be admitted that vascular tur gescence may cause this approximation of the parts, we would venture to suggest that some power of the nature of muscular contraction is necessary to give that degree of firmness to the union which it is found to possess some time after copulation.