66 THE SYNCYTIUM. 



i 



but never take the opposite direction. If the latter were true, 

 a far larger number of syncytial cells would be found in the 

 immediate neighborhood of the vessels of the ovular envelope. 

 The fact that all trophoblastic processes, short and long, carry 

 syncytium and that the arches of the trophoblastic lacunae are 

 almost completely lined with a syncytial coat can hardly be 

 brought into harmony with Pfannenstiel's claim, that the vessel 

 endothelium is transformed into syncytium and that starting from 

 here the syncytium gradually proceeds toward the ovum. 



Peters, with whom I agree, expresses the following precise 

 views concerning the genesis, the early appearance, and the loca- 

 tion of the syncytium (pg. 87.) : "We occasionally, though rarely 

 find within the trophblast, blood lacunae which as yet are not 

 lined with syncytium. Otherwise, however, the syncytium is 

 found distributed over the entire surface of the ovum, i. e., in all 

 sections of the complete series here and there we find bands and 

 masses of syncytial protoplasm varying in size, which either lie 

 flat on the trophoblast or are connected with it by a irregular net- 

 work of protoplasm or lie free in the blood lacunae or at times 

 push forward toward the Umlagerungszone." On these 

 facts Peters declares the syncytium to be a tissue of fetal origin 

 and my specimens have forced me to the same conclusion. 



This seems to settle the question whether the syncytium could 

 possibly originate from uterine epithelium or decidual tissue. 

 Peters has advanced so many and convincing arguments in oppos- 

 ing this view that I feel unable to add new ones. 



The following are some of the points in which my views have 

 changed as a result of the study of this youngest ovum and are 

 now at variance with views formerly expressed : The origin of 

 the Langhans' cells, the decidua of uterine epithelium in the 

 neighborhood of the ovum (already corrected on a previous occa- 

 sion), the origin of the intervillous spaces, and a few others. 



A further advance of our knowledge of this problem depends 

 upon the discovery of more very young human ova in situ, com- 

 ing if possible from patients who have died suddenly but not as 

 suicides. These specimens must be carefully preserved, pains- 

 takingly examined and the microscopic pictures reproduced in 

 illustrations which are true to nature. 



