During narcosis it was distinctly perceptible that the uterus was bifid down t,o the vaginal portion.
Thus the non-puerperal half seems to participate in the hyperplasia; but, as in most other cases of uterine reduplication, it could not be felt during pregnancy. Nor was the form of the organ abnortnal, any more than in uterus bicornis.
Delivery and the puerperium occur exactly as in uterus bicornis. Delivery at term from both uteri has not been observed.
The duplexities of the uterus have played an important part in the questions of super-fecundation. It seems certain that super-fecundation (impregnation of several ova of the same period by various coituses) occurs in animals, and it probably does in man, but super-fetation (im pregnation of several ova from various periods of ovulation and one preg nancy) is very doubtful. For though until the decidua unite, and even later (as in hydrorrhcea gravidarum), the path of the semen is open, yet ovulation does not occur while pregnancy exists, and super-fcetation seerns impossible. But it is different when extensive duplexity of the genital canal exista. Not only has the semen free passage to the ovary, but it is by no means so certain that all ovarian activity ceases when one side is impregnated. If the observations since Kussmaul's time are reli able, there seems to be a certain amount of independence of function in each side in these cases. Thus, in twin pregnancy one fcetus may be born, and the other uterus may remain quite passive, and only expel its contents much later. Menstruation, also, is peculiar; not only may the wombs al ternate, but the functions may be entirely independent. If one half is pregnant, the other menstruates normally through the entire pregnancy. All this points to a difference in the relation between ovulation and men struation in these cases and in normal ones; and the cases show that ovu lation can go on in the other ovary during gravidity. Thus super-fceta tion seems not to be impossible when there is marked duplexity of the uterus.
I am well aware that many cases can be urged against this view; cases where one fo3tus is cast off, and its twin goes on developing; where hem orrhages continue after pregnancy has set in; and I do not deny the diffi culty of bringing this hypothesis into union with our conceptions of the central organs. But it explains the occurrence of fetuses of different
stages at one time, or of the (same stage at different times, better than to suppose that one fcetus developed more slowly, or at times stopped de veloping. Besides, veterinarians do not deny the probability of super fo3tation in animals with uterus bicornis and uterus bicorporeus.
This diagnosis of uterus didelphys is certainly much easier than tbat of other faults of uterine development. The presence of a vaginal septum should excite in us suspicion of duplexity, but it is undoubtedly frequently overlooked, both during gravidity and outside of it. The presence of two completely separated vaginal portions speaks for a double uterus. For the uterine rudiments unite from below upwards, and if the cervices are separated, the bodies undoubtedly are. If, however, the cervices are applied to each other, a sound must be introduced into each os, and bi manual examination undertaken, best per rectum, to differentiate the condition from uterus bicornis. The finger can then be passed between the sounds, and the whole organs be demonstrated as separate; while in uterus bicornis the cervix uteri is simple, though it may be broadened. Possibly also the two halves in uterus didelphys will be more movable.
We must admit, however, that when the cervices lie very close to gether, or when the above-described connecting band is very thick, the differential diagnosis may be rather uncertain.
Unilateral blood accumulation can also be recognized easily. The condition of the os will enable us to decide whether the blood is in a double, or simply in a bicorned or bi-chambered womb. For in the two latter cases the partition wall takes part in the tumor of blood, mucus, or pus; the unclosed cervical cavity is dilated, and the os exter num forms a crescentic fold lying around the tumor. If, however, the open cervix is independent, as in uterus didelphys, the closed cervix does not influence it; its shape is unchanged, and the unclosed organ behaves like a simple organ displaced by any tumor. This is of importance also in the general differential diagnosis of pelvic tumors.