78 
OVARIAN PREGNANCY 
between a layer of necrotic tissue immediately applied to the villi, and the 
more healthy, living ovarian tissue forming the outer lamella of the wall 
of the cavity. A large coagulum was thus formed round the chorionic 
vesicle, and the whole constituted practically a “fleshy mole,” which would 
doubtless in a short time have been extruded from the ovary into the 
peritoneal cavity. 
The relations of the villi to the ovarian stroma are shown in our 
coloured drawing (Plate ix, Fig. 12). It represents a portion of the same 
section as figured in Figure xn, at a point where the villi have remained in 
close association with the connective tissue of the gland. An apparently 
normal villus showing both cyto-trophoblast and plasmodi-trophoblast, and 
some irregular masses of plasmodium are seen attached to the ovarian tissue. 
The connective-tissue lamella applied to the trophoblast is completely 
necrotic, and the deeper layers of the stroma show degenerative changes; 
at a still deeper plane the signs of degeneration gradually fade 
away, and normal connective tissue is reached. There is no reaction 
corresponding to the formation of the thick decidua in the uterus, 
and the destructive changes are much more pronounced; in fact, the 
appearances suggest the persistence of the early acutely destructive 
phase represented by the ovum which is described in the first paper. 
There are a number of mononuclear cells with large cell-bodies scattered 
through the ovarian tissue in the zone of attachment of the villi 
(Plate ix, Fig. 12). While some of these are probably of foetal origin, 
representing cells which have been cast off from large masses of 
Langhans’ layer cells, spread out over the surface of the necrotic 
zone of ovarian stroma, many are undoubtedly maternal cells. They 
may be swollen connective-tissue cells, or interstitial cells of the ovary. 
They are not unlike decidua cells, and if they be swollen connective 
tissue elements they would be analogous to the decidual cells in their 
mode of development, and would represent an effort on the part of the 
ovarian tissue to react as the endometrium does, but they are relatively 
so few in number that they do not constitute anything resembling a 
real decidua. 
The relation of the chorionic vesicle to the corpus luteum con- 
