THE EIANLAGE AND THE OVULAR CHAMBER (EIKAMMER.) 51 



tects it and possibly furnishes nutrition for that portion of the 

 ovular surface which as yet has not established its connection 

 with the maternal tissue." 



If we compare the histologic pictures of our specimen- with 

 this description, the sections 15 to 19 call for special attention, 

 because they plainly prove the minimal but quite noticeable es- 

 cape of blood from the ovular chamber into the fibrinous cover. 

 We have also seen how the left half of the fibrinous lid has be- 

 come more and more organized and in this way reenforced the 

 decidual envelope and how to the right the large head of the 

 fibrinous band, which lies in an indentation of the ovular cham- 

 ber, closes the opening of entrance. 



Still other similaraties can be detected. In Peters' ovum 

 (Plate III, Fig. 4) there is also a lateral and central depression 

 in the fibrin plug, so that the fetal ectoblast almost immediately 

 touches it. On the other hand in his specimen the trophoblast 

 processes also penetrate into the decidual layers over the sum- 

 mit of the ovum, so that in some places they become extremely 

 thin and appear worm eaten. 



Finally, it shall here be mentioned (Peters, pg. 44) that the 

 envelope of the embryo of Graf v. Spec was surmounted by a 

 flat blood coagulum. 



III. 



THE EIANLAGE AND THE OVULAR CHAMBER 

 (EIKAMMER). 



\Vc have seen that the o.vule has burrowed itself, gradually 

 pushing aside the decidual tissue. Some of the glands were dis- 

 solved, others displaced. The blood vessels were in a state of 

 ^narked congestion, multiplication and coalescence. This shows 

 clearly how the ovular chamber, especially its summit, consists 

 <of decidual tissue and how large blood spaces adjoin its inner 

 surface. These blood spaces are divided by trophoblastic col- 

 umns and communicate directly with the surrounding capillaries 

 situated in the wall of the ovular chamber. 



In the next chapter these intercommunicating capillaries and 

 irophoblast processes with their attachment to the inner surface 

 oi the ovular envelope, shall be considered. 



Here we shall first of all speak in general of the "Eianlage v 

 (Fig. 18, Plate X). An exact idea of the form of the Eianlage 



