Embryonic Development in Man. 379 



logon of the periblast of transparent pelagic fish eggs, such as those 

 of Fundulus, which I had a chance to study in the Summer of 

 1899, in the Woods Hole Marine Biological Laboratory, under the 

 direction of Professor C. O. Whitman. In these fish eggs the for- 

 mation of the periblast- — an outer capsule of plasma without cell 

 boundaries, but with numerous nuclei — can, of course, be studied 

 from stage to stage under the microscope, and the expulsion of nuclei 

 into the plasma can be seen. 



In spite of the fact that the syncytium of the human placenta does 

 not deserve this name in the sense as originally applied, it is well 

 to preserve its use, since it has been universally applied to the outer 

 covering of the trophoblast, and of the later chorionic villi. For 

 degenerative confluent cell masses in the placenta, whether they be 

 of maternal or fetal origin, Bonnet has proposed the term symplasma, 

 and he distinguishes between symplasma maternum and symplasma 

 fetale. These terms have been accepted by Jung in the descrip- 

 tion of his ovum, and we will likewise introduce them into our 

 considerations. Some of the German writers on placentation, fol- 

 lowing Bonnet, have come to use the terms "Grundschicht," for the 

 cellular part of the '' Trophoblast" (the later Langhans layer), and 

 "Deckschicht," for the syncytium. 



The General Position, of the Ovum and its Mode of Entrance into 

 the Decidua. 

 At the time of the autopsy, as stated above, the ovum, or rather 

 the small hemorrhagic spot, was found at the posterior wall of 

 the corpus uteri, comparatively high up in the fundus, and near 

 the entrance of the left Fallopian tube; that is, on the same side 

 where the corpus luteum ovarii was noticed. The dark, hemorrhagic 

 spot which contained, as was later on found, the ovum was only 

 very slightly prominent over the remainder of the thick, velvety 

 mucosa. The uterus, after the careful removal of the dark spot, 

 which was excised as a cubical mass, was preserved in the patho- 

 logic collection of the Government Laboratory, but I have not had 

 a chance to re-examine it during my stay in Manila, and I do 

 not know whether it has been preserved permanently or not. 



