82 
OVARIAN PREGNANCY 
tissue all round its free surface. On the deep aspect of the ovisac 
and somewhat spread out round its base, there was a large corpus 
luteum. This enclosed a large cavity filled with organising blood 
clot and fibrin, and on one aspect came into direct contact with 
the foetal tissue. Here the wall of the body diverged so that the 
chorionic vesicle appeared to rest in its widely splayed-out mouth. All 
round the circumference of the ovisac portions of lutein tissue were 
found, though always in the form of a thin interrupted layer. This 
layer of lutein tissue was not however in contact with the villi of the 
chorion ; it was everywhere separated from them by a thin lamella of 
fibrous tissue which formed the actual investment of the chorion. The 
lutein tissue did not behave like decidua, and indeed played no part 
in the attachment of the ovum. As the authoress rightly points out, 
the tissue in which the ovum was imbedded represented the young 
connective tissue which is formed within the lutein tissue or theca 
interna, in the first stage of organisation of the contents of the rup¬ 
tured follicle. No formation like a decidua was present, though at 
first, until she recognised its true nature, the authoress thought that the 
broken layer of lutein cells represented decidua ; the only reaction 
on the part of the ovary to the needs of the growing ovum, was a 
great increase in the vascularity of the stroma. 
The chorionic vesicle was covered all over by villi which showed 
precisely the same structure as those of an intra-uterine vesicle of the 
same stage. The embryo measured 12 mm. and was perfectly normal 
in appearance. 
II., Ill —Cases of Kelly and MTlroy, and of Mendes de Leon and Holleman. 
In the specimens described by these authors there was no formed 
corpus luteum, but lutein cells were found in the wall of the implantation 
cavity. In the first-mentioned case the lutein tissue was separated 
from the villi by a thin layer of fibrous tissue, and the conditions of 
implantation were practically identical with those in van Tussenbrcek’s 
case, but the corpus luteum had apparently been distended and 
