AN EARLY OYARJAN PREGNANCY 
INTRODUCTION 
The literature of ovarian pregnancy takes us as far back as 1614, when 
Mercer first suggested the possibility of its occurrence. There seems to have 
been a common belief that the ovum might be implanted and could for 
a certain time develop within the ovary. No demonstrative histological 
evidence was however forthcoming, and as data regarding tubal pregnancy, 
and the varieties it may assume, accumulated, it became increasingly doubt¬ 
ful whether the early records were not due to inaccurate diagnosis. This 
opinion was expressed by such authorities, as Lawson Tait and Biand- 
Suttoi). In 1899, however, a careful histological description of an early case 
was published by Catherine van Tussenbrcek, by which she demonstrated 
beyond question that the ovum could be imbedded in the ovary. Since 
then her main conclusion has been confirmed by a number of observers, 
and it is now universally admitted that such an implantation, remarkable 
as it may seem, does occasionally occur. 
The details of the process of imbedding in the substance of the ovary 
are not however fully known, nor completely understood. The desideratum 
is a still earlier chorionic vesicle than any yet described implanted in the 
gland. Catherine van Tussenbrcek considered that her case proved 
that the essence of ovarian pregnancy was implantation of the ovum in 
a Graafian follicle, but other cases since published do not all bear out 
this conclusion. The specimen which we have to describe shows that 
imbedding may occur outside the follicle, and it is especially valuable 
in respect that the stage of development reached by the chorionic vesicle, 
