THE MUCOUS MEMBRANE ELEVATION. 39 



The mucous membrane elevation in which his ovum lies, pro- 

 trudes but slightly and still has a superficial epithelium covering 

 its margin. The glands are greatly dilated, lie around the ovum 

 meridionally and also have no communication with the ovular 

 chamber, the latter pressing them aside. In his sections also vari- 

 ous uterine glands (Plate I) are seen filled with blood, the sur- 

 rounding of the ovum containing an enormous wealth of greatly 

 dilated capillaries which in part are changed .into wide blood 

 spaces exactly as in my specimen. In his Plate I, a large blood 

 space is seen to the right and below, like an extravasation sur- 

 rounding almost half the periphery of the ovum, communicating 

 freely with those blood lacunae in which the trophoblastic pro- 

 cesses are directly immersed. 



Although the similarity between Peters' and my specimen is 

 striking, still attention must be called to certain apparently ex- 

 isting differences. In Peters' specimen the trophoblast every- 

 where lies in direct contact with the inner wall of the envelope 

 of the ovum and an embryonic rudiment is plainly visible. In 

 my specimen, on the other hand, the trophoblast has not as yet 

 everywhere reached the inner wall. It still partly floats, in the 

 blood which fills the ovular chamber. In spite of repeated and 

 careful examinations no trace of an embryonic formation could 

 be detected. 



Whether this floating of the trophoblast in the blood of the 

 ovular chamber and the absence of an embryonic "Anlage" is pos- 

 sibly only due to a pathological extravasation of blood between 

 the ectoblast and mesoderm, is still a question which, must be 

 decided later. This difference, which in this connection is simply 

 registered, is striking and might warrant the question, whether 

 the ovum in my specimen is not possibly a few hours younger 

 than that of Peters, and, whether within the next one-half day the 

 junction between the trophoblast and the inner wall of the ovular 

 envelope would not have been completed. This, however, must 

 'remain a mere assumption until other specimens of such an early 

 stage have been found. 



At any rate the same vascularity which is observed in our two 

 specimens, is also found in the uteri of animals. "The changes 

 in the maternal mucosa surrounding the ovum, in the various 

 mammalia, are differently described. A formation of new ves- 

 sels in the immediate neighborhood of the chorion, often to a 

 great extent, is regularly found. In advanced stages noticeable 

 vascular changes also occur in the deeper layers of the mucous 

 membrane 1 ." 



"Very important are the results of researches made on animals 



1 Pfannenstiel in Winekel 1. c. pg. 198. 



