60 THE TROPHOBLAST AND ITS SURROUNDING BLOOD SPACES. 



Correctly we cannot as yet speak of intervillous spaces be- 

 cause the mesoderm has not yet entered trophoblastic process so 

 that villi in the strict sense of the word do not exist. In Peters' 

 specimen (Plate II) they have already formed. Therefore, it 

 would be more appropriate in our ovum to apply to these blood 

 spaces the term "intertrophoblastic." 



It seems, however, not desirable to add new difficulties by in- 

 troducing a new term. The reader acquainted with the subject 

 will know what is meant and it would seem permissible to speak 

 of an "Anlage of intervillous spaces" even in this stage, since 

 very soon villi actually will enter these trophoblastic excres- 

 cences. 



What can be attributed to the findings? 



I am well aware of the fact, that although it lies completely in 

 situ and has been carefully handled, still it shows in a few sec- 

 tions, an excessive amount of blood which, here and there, has 

 pressed the Eianlage together and detached the ectoblast. Ow- 

 ing to this I hesitated in publishing my findings, but since in the 

 main all those conditions which I wish to demonstrate were so 

 plainly visible, and so instructive, I was finally persuaded to do 

 so by 'Prof. Graf v. Spec. 



I believe that the description of my ovum is of value so long as 

 no other ovum of the same age or possibly a younger one still 

 better preserved is known. I will therefore compare my find- 

 ings with those made on the youngest ovum known in literature. 



Peters has extensively quoted all those writers who have de- 

 scribed older ova and carefully compared his findings. Thus I 

 am justified in limiting myself here to his description and his 

 critical review of the literature on the subject, and shall empha- 

 size only points of importance in these new findings. For a con- 

 sideration of this subject, only a few of the recent contributions 

 will be considered, and this will also appiy to the following chap- 

 ter dealing with the syncytium : Pfannenstiel in Winckels Hand- 

 buch der Geburtshilfe, Rossi Doria, 1 Marchand, 2 Friolet, 3 Herr- 

 mann and Stolper, 4 Webster, 5 Graf v. Spec and Beneke 1. c. 



Peters' description of the trophoblast corresponds in all es- 

 sential features with ours. He found the development, the 



1 Ueber die Einbettung des menschlichen Fies. studiert an einem kleinen Ei der zweiten 

 Woche. Arch. f. Gynaekologie 76. 



2 Beobachtungen an jungen menschlichen Eiern. Anat. Hefte. 21. B. 



3 Beitrag zum Studium der menschlichen Placentation. Leipzig, Thieme. 1904. 



4 Zur Syncytiogenese beim Meerschweinehen. Wien, Hoelder. 1905. 



5 Die Placentation beim Menschen. Uebers. von Kolischer. Berlin, O. Coblenz, 1906. 



