MALFORMATIONS OF THE OVUM.
1. Mola botryoides or hydatica,— Hydrometra aquatica,—is a degeneration of the chorion into vesicles of different sizes, filled with a serous liquor, which were erroneously taken for hy datids. They cover the surface of the en larged ovum, and are the villi of the chorion, which, as no formation of vessels took place, retained their original vesicular form (Ruysch, Albinos, Sandifort, Cruveilhier, Velpeau). Sometimes a foetus is found in it, which, how ever, in relation to the ovum may be said to be small.
The small embryo most probably dies in the early period of pregnancy, and the degenerated ovum continues to grow till a later period, when it is evacuated. In most cases abortion is the consequence of this condition of the ovum. Sometimes, nevertheless, the pregnancy lasts till the full time (Gregorini), or sometimes longer, as happened in a case observed by Lossins, in which it lasted six years. Sometimes the foetus disappears, and then this degenerated vesicular mass is evacuated alone, with ex cessive hemorrhage and great pain. This is the last period of what is called false preg nancy.
The vesicles are inclosed in a kind of de cidua ; they are fixed on pedicles, from which arise other vesicles with smaller stems, so as to give to the whole the appearance of the chorion, in an earlier period of its existence, when the villi still preserve their original vesicular form. The accurate observations of Boeck show that, in most cases, these vesicles contain blood, which sometimes can be dis placed by pressure from the one to the other vesicle, or is coagulated. The internal sur face of the membrane which forms the vesicle is smooth, the external interwoven with fibres. A thus degenerated ovum has not the power of bringing the foetus to a state of perfect maturity. The death of the fmtus and mis carriage are its consequences. Sometimes the Moles botryoides is accompanied by malfor mation of the foetus (Valisnieri).
From this degeneration ought to be distin guished ; 1st. The vesicular degeneration of the placenta, when retained after a natural parturition in the womb (Gregorini) ; 2nd.
The Polypi fugaces or vesiculares evacuated in the anni climacterici by elderly women (Lev ret) ; 3rd. Those after suppressed menstrua tion in unpregnant women (Schleierbach, Watson, Sporing, Lisfranc). As I have no ob servations of my own of any of these cases, 1 dare not pronounce any opinion about the affinity of these vesicles to the Mola botryoides.
2. Separation of the placenta into lobes or cotyledons. This is without doubt to be attributed to an arrest at a lower degree of developement, and it offers some resemblance to the placenta of the Ruminants. The smallest amount of deviation is a division into two coherent lobes, which are separated only by a small constriction (J. F. Meckel, Ebert). Such a placenta has an oblong form. Sometimes there is a single lobe adjoined to the placenta (placenta succenturiata); it is of much smaller dimensions than the placenta itself, and united to it by vessels, without a cord. The placenta may also be divided into three (Rohault, Schwencke), four (Hoboken), five (Meckel), or seven lobes (Kerckring, Wrisberg). In the observation of Kerckring, the arrest at a lower stage of development is clearly shown by the presence of the Vena omphalo-mesenterica.
3. The vessels of the umbilical cord are sepa rated near the placenta, and meet at a con siderable distance from it (Sandifort, Wrisberg, Adolph). In one of the published cases, this disposition of the vessels was the cause of their rupture, which produced the child's death by hemorrhage. Sometimes they were ob served to run separately from the placenta to the abdomen of the foetus, into which they penetrated through separate openings. In most cases they meet each other just at the umbilicus (Gavel, Van Solingen).
4. The umbilical cord too long.—The com mon length of the cord is twenty inches (Roederer, Wrisberg), but it may be forty eight inches (Wrisberg), sometimes even five feet (Morlanne). The usual effect of such an abnormal length of the cord is a circumvolu tion of it round the body of the foetus. An example of it is given in a very misformed foetus in fig. 597.