Here the entire organ was widely separated, even the cervices, and the case is one which is beyond dispute.
Each half of the uterus didelphys conforms in position, shape, and adnexa to a uterus unicornis without rudimentary horn. The bodies are entirely separated, and the cervices, though distinct, are separated by a membrane which ends above in a free border. This membrane is com posed of connective tissue, fat, and elastic fibres; and it contains no smooth muscular fibres. Its thickness varies as the two halves are more or less separated. Even if both cervices lie side by side, and there is no connecting membrane, each half is independent. Of course the diagno sis may be difficult in the living subject, especially as transition forms between this and uterus bicornis occur It is remarkable that, though we have but few post-mortem records of these cases, the ligamentum vesico-rectale is not mentioned. It must occur, and, as we have seen, it is sometimes marked in cases of uterus bicornis.
The vaginal partition may be complete, and it is common to both canals. Or it may be incomplete, merely dividing the vault. Or again, the vagina may be entirely simple, or its division be only indicated by a s.ckle-shaped projection in the vaginal vault.
Atresias can occur here as in the other duplex conditions of the geni tals, and lead to the same results.
The cause of uterus didelphys must take effect early in the first period, before the Milllerian ducts have approached one another and coalesced, before the eighth week of embryonal life. Undoubtedly the simple organs, which normally lie before and behind the uterus, push themselves in be tween the Miillerian ducts, and prevent their union. Tlais we see mos: plainly in those non-viable deformities in which there is abdominal, vesi cal, and pelvic fissure. The umbilical vesicle is drawn strongly dovrn wards, and thus the closure of the lower part of the abdominal wall is prevented. This tension is transmitted to the intestines, which are thus drawn down between the two lateral rudiments of the internal genitals. This, however, does not explain the existence of the abnormality where there is no vegical fissure and consequent intestinal tension. Here those
deformities which are dependent upon an over-distension of the allantois or bladder, and of the intestine or rectum, may help us. These are mostly dependent upon atresia of the orifices of these cavities. These dilated organs may entirely or only partially prevent the approach and c,oales cence of the Miillerian ducts. They also cause uterus bicornis; but here they begin to act only when union of the lower parte of the ducts has al ready taken place.
But to the vesico-rectal ligament belongs a great share in the causa tion of these deformities. We cannot at present say positively that it is a rudiment of some embryonal structure. The vesical and intestinal canals may later return to their normal size; and the peritoneum between them, which had not developed as usual while they were in apposition, is put on the stretch, and developed into a fold. This fold would then go on t,o develop as the other organs do, and, like other peritoneal re duplications, may contain muscular elements from the uterus.
Another explanation may be given by the inflammatory processes which undoubtedly play 80 important a part in the etiology of these ab normalities. Adhesive inflammation may unite the contig-uous surfaces of bladder and rectum; and when the organs contmct again, the ad hesion is stretched into a band. It is no objection that there are no ci catrices; for we know that atresias occurring in childhood not infre quently leave no scar tissue. And Schatz says that in his case, in which the ligament in question was very well-developed, there were also other bands which united the coils of the ilium to one another. This was the case in Winckel's two cases, and in the case of atresia ani recorded by Th.
Weiss. But it is more difficult to understand how an inflammatory band can, like a normal one, subsequently develop into the ligaments which Winckel and Cassan have figured. In Freudenberg-Schroder's case of uterus didelphys, the rectum was found between the two halves, and ad herent to them.