52 THE EIANLAGE AND THE OVULAR CHAMBER (EIKAMMER.) 



could be gained only by a reproduction of pictures of all consecu- 

 tive sections, which, for obvious reasons is impossible. 



Studying only Fig. 18, the sections 60 to 70 and 80 and 81 

 in rir.te XI, Fig. 21, one gains the impression that a somewhat 

 irregularly shaped structure lies almost in the center of the 

 ovular chamber from which mesodermic processes extend from 

 all sides. Some of these processes are covered with an ectoder- 

 mal layer (Fig. 18 ekt.). 



Here and there the ectoblast layer (e. g., at ek^) is detached 

 by an extravasation of blood under it. This does not seem 

 to be normal. At present, however, we must leave the ques- 

 tion undecided how far this condition is pathologic or still physio- 

 logic in this earliest stage of development. The number of very 

 young human ova so far known to us is still too limited, on the 

 other hand in our case the ovule and the entire mucosa of the 

 uterus is so well preserved that this one feature, even if patho- 

 logic, could not diminish the value of the other fiindings. 



Considering the form of the Eianlage as it appears in our own 

 specimen, we find in a series of consecutive sections that it is at- 

 tached with a broad base to the inner wall of the ovular cham- 

 ber near its summit (Fig. 18 a). This attachment is firm and 

 the tissue is here also slightly permeated with red blood cells. If 

 permitted to make a comparison one could say that the ovule 

 sticks like a leech with its head to the inner wall of -the ovular 

 envelope, while the rest of the body is suspended in the cavity. 

 In order, however, to avoid any misunderstanding it is here 

 stated that already in this stage long trophoblastic processes ex- 

 tend from the irregularly shaped Eianlage (Fig. 18, tr, tr, Plate 

 X) which are attached to the chamber wall, and in this way, like 

 thin threads, fasten the apparently floating ovum. 



Even under very high magnification this Eianlage is appar- 

 ently composed only of a congealed mass, traversed here and there 

 by structureless, very delicate fibres, the latter passing chiefly 

 along the sinuous periphery of the Eianlage. The actual contour, 

 however, in the main is formed by small round or oblong cells 

 with deeply stained nuclei which in connection with the trans- 

 parent network of fibres create the picture of villous tissue, i. e.. 

 of the "Anlage" of the mesoderm. 



Before entering into a consideration of the trophoblast and its 

 attachment, it may be well to recapitulate what has been said 

 before. It seems important ' to have a clear conception of the 

 condition of the ovum after it has entered the mucosa and of 



