From vehat has been said, it may be concluded that in nulliparte the vaginal portion and the glans are seldom brought in contact, and that in women who have often borne children the two openings seldom correspond, and. that .11 complete descensus uteri and a parallelism of the axes of both canals, likewise an upward suction of the semen from the side of the cervix, is highly improbable, There remains now nothing but the action of the muscular tissues of the vagina and the pelvic floor and the ejaculatory force of the penis. We will pass over the first; the latter is certainly no weak force, and is capable of dilating the lax and loosely together lying walls of the vagina for a short distance; but whether it is sufficient to force open the narrow and rigid cervical canal—and even if this does occur, the conditions must have been very favorable--is very doubtful.
There remains, therefore, as the principal factor in the advancement of the semen, nothing but the specific movements of the spermatozoa., which are only aided by the contraction of the vagina. The semen, de posited on any part of the vagina, traverses the vaginal c,anal by means of the same force which moves it forward in other parts of the genital tract, where the conditions are no more favorable. It is indeed true that the nearer the external os the deposit occurs, the more favorable are the pros pects for its transmission into the uterus. But for this it requires a particular contrivance, as the poche copulatriee of Courty, not the recep taculum seminis of Beigel, in which apparatus the semen inay collect, and into which the vaginal portion may dip for the purpose of taking up the semen. In the vaginal vault there exists no hollow space, but the anterior vag-inal wall with the vaginal portion of the cervix lies directly upon the posterior vaginal wall. A very small quantity of semen carried into the upper part of the vagina is sufficient to moisten the correspond ing surfaces of the vaginal canal. This may easily be proven by a simple experiment. By introducing without force by means of a delicate syringe, only a few drops of a staining fluid, for instance, India ink, into the upper portion of the vagina, it is easily seen, upon the careful introduc. tion of the speculum, that the whole vaginal vault is stained thereby. All parts, with which the external os comes in contact, are of a blackish color. Although the seminal fluid is somewhat thick, its consistency is not such as to prevent its spreading in a similar manner after its ejacula tion into the vaginal vault, and thus coming in contact with the external es. Therefore more than sufficient semen for the further advance through the cervical canal finds its way to the external os without any particular dispositions. In the normal condition of the cervix, the passage of the
semen is accomplished by the same foroe which chiefly moved it forward in the vagina. The cervix is normal when its canal throughout its whole extent, but particularly at its two openings, shows a sufficient diameter; when the canal is not occluded by secretion, and when the latter is of the proper chemical reaction (weakly alkaline). Even for this part of the genital tract, auxiliary forces have been claimed in the transportation of the semen. It is claimed that the ejaculation not only propels the semen into the c,ervix, but also through its canal directly into the uterine cavity (J. T. Ho1st). Aside from the fact that it is highly improbable that this force um propel the semen into the cervical cavity, the arbor vita uterinm would certainly hinder the accotnplishment of this occurrence. A glance at the cornplic,ated structure of the cervix in the animal kingdom (in the pig, sheep, etc.), where the mucous membrane is disposed in markedly projecting folds and flaps, and offers the greatest obstacles to the onward movement of the semen, is in this respect very instructive; this arrange ment, which repeats itself, although in a lesser form, in the human species. shows us that the semen must rely upon its own strength to pass through this canal. Peristaltic movements of the rigid walls of the human uterus are not t,o be thought of. The movements of the ciliated epithelium are undoubtedly directed toward the uterine cavity; they can aid the forward movement of the semen, but they cannot have a very important signifi cance, since in the tubes the spermatozoa hasten toward the ova against the ciliary motion, and without being very much retarded by it. If we call t,o mind those pathologic,a1 changes of the cervix which exclude all these auxiliary aids, and in spite of which conception occurs, we must admit that, in this portion more even than in the vagina, that quality of certain cells and their derivatives, which otherwise also plays such an important part in physiology and pathology, namely, the automatic change of locality, aids the transportation of the semen. After the semen has reached the uterine cavity, it does not meet with any arrangement, whereby its further transportation will be accomplished; here also the semen is relatively dependent upon its organized elements. This power of self-movement is so great, that the spermatozoa traverse the narrow est part of the genital tube, namely that portion of the tube which pene trates the wall of the uterus, in a tortuous manlier, even against the ciliary motion of the epithelial cells, only to overcome in the middle portion of the Fallopian tube the opposing peristaltic movements, in order that they.