THE MIGRATION OF VTR SPERMATOZOA.
From lack of direct observation, as well as by the ambi guity of the results of investigations which have been instituted into the further advance of the semen, and from the greater or lees value which one attaches to certain experiments upon animals, this divergence of opinion is easily understood, and great freedom is given to theoretical speculations. Two opirtions are directly opposed to each other. Accord ing to one, the proper transportation of the semen is directly from the orifice of the male urethra into the external os uteri, which openings dur ing cohabitation so approximate themselves, that not only do they corre spond, but the elongated axis of the penis is identical with the vertical diameter of the cervix; the force, with which. the ejaculation occurs, transmits the semen directly into the uterus. The vagina does not serve as a receptacle for the semen, but only, as its name indicates, as a canal through which the penis accomplishes its approach to the uterus. Ac cording to the other diametrically opposed view, the semen is simply de livered into the vagina, and the spermatozoa by their own peculiar move ment bring about their transportation into the uterus. As in all (Ages, where extremes stand opposed to one another, so here there are inter mediate views.
As regards the first view, it is an ideal one, which, in no way, corre sponds with the truth. Aside from the fact that the anatomical structure of the genitals of a large number of animals would not permit of such a process of coition, there are many important considerations in the human species opposed to its unqualified acceptance. I would point to those not infrequent cases, which we must speak of later, where impregnation occurs without intromission, and where, therefore, the semen must un doubtedly traverse the long vaginal canal; if it be claimed for such cases that the seminal ejaculation occurs directly against the opening in the hymen, the ejaculation still lacks that force to so widely separate the walls of the vagina as to permit of its encountering directly the external os. Further, early in the marriage state in a great number of nulliparte, conception occurs at a time when it is certain that the penis could not have penetrated deeply enough to have reached the highly-situated vagi nal portion. Further, without t,aking into consideration the fact that from the position of the uterus, its axis is quite different from that of the vagina, so that on account of this condition, a direct injection into the cervical canal cannot occur, it is very improbable that two such small openings as the meatus urinarius and the os externum should meet each other with such certainty. But in women, who have already borne chil dren, where, therefore, nothing prevents the deep penetration of the penis, even to the root, and where the relative patency of the os externum Savors the taking up of the semen, the vaginal fornix is of such a width and often of such laxness that the glans is by no means compelled to ap proximate itself directly to the vaginal portion.
Seeing the improbability, nay more, the impossibility of such an occur rence, it became necessary to claim other factors as aids. In this way the uterus is made to encounter the virile member, and coincidently to as sume such a position and relationship, that the respective canals lie in the same direction. Now, aside from the fact that we hardly dare sup
pose that the uterus would spontaneously descend as deeply as we would draw it down in operations, only by the exercise of great force, or that, for instance, the external os would seek that small gap which may re main open in a transverse obliteration of the vagina, it is hard to find a power which would occasion such a movement of the uterus. Now it is that the compression suffered by the anterior abdominal wall during coitus is introduced; butt this pressure alone is not exerted directly upon the uterus, as is the case, for instance, in bi-manual examination, but am only influence the uterus by an increase of the intra-abdominal pres sure, and therefore only in a minor degree; the influence of the abdomi nal pressure, which otherwise plays an important role, is excluded, since the respirations in the act of coition, in consequence of the sexual excite. ment, are not suspended, but are increased. The muscles of the uterus an. absolutely incapable of forcing the uterus downward; only those mus cles which are contained in the ligainents are in a condition to cause a change in its position. But if we picture to ourselves the direction of the action of these muscular fibres, we find that their power is not favor able to such a movement as we have just spoken of. The sacro-uterine ligaments draw the cervix upward and backward, and therefore place it in a position in which its axis is directly opposite to that of the penis; the ligamenta lata and rotunda, which undoubtedly draw the fundus of the uterus, elevated by, pregnancy, downward, pass in the unimpregnated. uterus lying in the pelvic inlet in a different direction. The first of these could, acting singly, only draw the uterus laterally toward the pel vic walls, while the action of both lateral ligaments would only serve to fix the uterus in the pelvic inlet, and the ligamenta rotunda would draw the fundus forward, and therefore would carry the external os out of the axis of the pelvis, and approximate it to the posterior pelvic wall. Thereby it is given an altogether improper position. After these there are only the longitudinal muscular fibres of the uterus remaining. These, according to the testimony of anatomists, are poorly developed; but their traction is certainly negatived by the coincident contraction of the more powerfully developed circular muscular fibres, the constrictor vagilus superior of Sims. That the latter, probably, in connection with those muscular fibres contained in the uterine ligaments, are also capable of drawing the uterus downwards, can indeed be proved by the experiments. made upon animals by Kehrer, Basch and Hofman, but certainly the power is not sufficient to cause such a physiologically productive descent, as is claimed for it theoretically; at least I consider it very improbable in those women who have not borne children. In such women, a some what more forcible expenditure of power is required to draw the uterus a short distance downward, even for diagnostic or therapeutic purposes; I can hardly believe that the tolerably weak muscular apparatus above mentioned is capable of a similar exertion of strength.