THE EMBEDDING OF THE OVUM. 45 



tion. The point of entrance in our case has become almost com- 

 pletely obliterated, but there still persists a narrow channel from 

 which some blood oozes, the latter accumulates at the summit of 

 the ovum and becomes transformed into the fibrinous cover. 



It Peters' specimen the connective tissue does not as yet form 

 so complete an envelope as in mine, in which the ovum has 

 possibly already penetrated to a greater depth. In his case, there- 

 fore, the opening still existing in the decidual envelope is covered 

 by a broad layer of fibrin partially organized. It is called by him 

 the "Gewebspilz." The trophoblastic processes with their syn- 

 cytial excrescences are directly attached to it 



Concerning the clos.ure of the defect through which the ovum 

 has penetrated, 'Pfannenstiel (1. c. page 220) has expressed him- 

 self very carefully. Since at that time Peters' specimen was the 

 only one known, he considered the process of closure as uncer- 

 tain. Descriptions of very young ova as given by Peters, Graf von 

 Spec, Heukelom, Leopold and Keibel had stated "that at the point 

 of closure not a distinct decidual tissue but a scar tissue is found, 

 consisting chiefly of fibrin and showing an absence of blood ves- 

 sels, also he himself was able to confirm the presence of this 

 fibrinous scar tissue, he would not consider this question defin- 

 itely settled since the formation of fibrin within the decidual 

 envelope of the ovum is very common and often can be traced 

 to an entirely different cause. It would seem possible that the 

 final closure of the decidual capsule around the ovum is accom- 

 plished by a firm coalescence of the vascular connective tissue 

 which proliferates from opposite sides. At this place, which is 

 the most poorly nourished portion of the reflexa, soon after- 

 wards signs of degeneration would appear especially so in ova 

 which are more superficially embedded. The blood plug of 

 Peters thus might possibly be considered an abnormal condition.'' 



The assumption of Pfannenstiel that the ovum has an entirely 

 decidual envelope is confirmed by my case, with the exception 

 of that narrow opening at e. s. As mentioned before, it is 

 caused by a deeper implantation of the ovum. Nevertheless, there 

 is in our case, like in that of Peters, a large and very broad 

 fibrinous cover lying over the top of the ovum, so that such a 

 cover must form even in case of complete decidual inclusion. In 

 any explanation, however, of the origin of this fibrinous cover 

 one must consider this narrow opening through which the ovum 

 sank (e. s. Fig. 5 & 6) and whence that tiny amount of blood 

 has oozed to the surface and there coagulated. 



In order to obtain a clear conception of this fibrinous lid one 

 must first of all gain a precise idea of its form, length, width and 



