58 THE TROPHOBLAST AND ITS SURROUNDING BLOOD SPACES. 



cases the manner in which the ends of the trophoblast processes 

 become fixed to them is the same. It is effected by means of 

 smaller and larger single syncytial cells, at times by groups of 

 them which glue these processes to the decidual tissue. 



How intimate this attachment may become which, especially 

 in the tissue of the summit of the ovum, could be called an an- 

 choring, can be seen in Fig. 11 (Plate VII). Here the tropho- 

 blast, together with its adjoining syncytial cells, has buried itself 

 deeply into the decidual coat and advanced to "sy" with one large 

 giant cell. A similar condition can be observed in Fig. 11 at tr 

 and tr 1} where the syncytial cells radiate from the trophoblastic 

 processes in various directions. 



In the periphery of the ovum the connecting syncytial cells at- 

 tach themselves to the nearest decidual trabeculae or to the re- 

 maining portions of the walls of the enormously dilated and rup- 

 tured capillaries and blood vessels. Hereby a connection of the 

 latter with the blood lacunae is established and maintained. 



The syncytium therefore does not only serve the important 

 purpose of fastening and anchoring the trophoblast, but during 

 the further development of the ovum brings about the gradual 

 dissolution of more capillary walls (Fig. 28 Plate XVI) and in 

 this manner constantly provides larger and larger blood spaces 

 for the sustenance of the ovum. 



Now that we have become acquainted with blood spaces which 

 lie between the trophoblastic processes (ad. 3), it will be neces- 

 sary to explain (ad. 4) the relation of these blood spaces to the 

 confluent capillaries in the surrounding decidual tissue. For this 

 purpose sections 81 to 96 and also Figs. 22 & 23 (Plates XII & 

 XIII) must be studied. 



In looking over these sections one must keep in mind the 

 fact that the ovum has entered a tissue which as a result of the 

 premenstrual state was highly congested. Blood vessels as well 

 as glands were greatly dilated. Blood extravasated from the cap- 

 illaries, passed into the interstitial tissue and finally also found 

 its way into the glands. Thus the Kianlage was surrounded and 

 the ovular chamber formed by a very loose and spongy tissue 

 infiltrated with blood consisting in the main of dilated capil- 

 laries, many of them ruptured. 



No matter how many specimens we examine and compare, the 

 same condition will be noticed in all. The inner wall of the 

 ovular chamber, as already mentioned, is formed partly by di- 

 lated capillaries and partly by open blood spaces with their inter- 

 vening framework. Since the open blood spaces only recently 

 have been closed capillaries, their inner wall, not everywhere but 



