642 
two months there being a thicker inner and a thinner outer fibrine 
layer, while between them is a stratum, in which remains of cells are 
seen; occasionally is an appearance, which suggests a surviving deci- 
dual cell, and nearer the placenta the phantoms of cells become di- 
stinctly cells and true decidual cells can be made out. The inner 
fibrine layer is much denser and its meshes smaller than in the two 
months specimen, the trabeculae of fibrine having become during the 
month elapsed. 
The relations of the amnion and chorion to one another in a 
uterus of seven months I have already described and illustrated in 
detail in my article „Uterus and Embryo“ (Journal of Morpho- 
logy, Vol. II, 422—425, Cuts 33—33). I will recall only that the 
chorion lies directly against the decidua; between the chorionic meso- 
derm and the decidual tissue extends a layer of epithelioid cells, 
which I interpreted as the modified ectoderm of the chorion, a view 
which I still hold. Of a membrane between the chorion and the de- 
cidua there is no other trace. 
Those who conceive that there is a fusion between the reflexa 
and vera are forced to seek for traces of the former membrane next 
the chorion. They may assume either that the epithelioid layer is 
the remnant of the decidua, which forces them to leave the fate of 
the chorionic epithelium unexplained or that the upper stratum of the 
decidua is the reflexa, which is fused with and acquired the same 
structure as the underlying vera. If my observations on the degene- 
ration of the reflexa are correct and correspond, as there is sufficient 
ground to believe they do, to normal conditions, then both assumptions 
as to the persistance of the reflexa involve the further and very im- 
probable assumption that the degenerated tissue is removed and re- 
placed by fully organized cellular decidual tissue. It is obviously 
more in accordance with our knowledge of degenerative changes to 
assume that the hyaline metamorphosis is necrotic and is succeeded 
by the disintegration and removal of the tissue. This accounts in 
a satisfactory manner for the absence of the decidua reflexa during 
the sixth and seventh month. The relations of the membranes at 
this period have been well described and figured by an admirable 
observer Dr. G. LEOPOLD, whose views and one of whose drawings 
have been incorporated by Prof. O. Herrwic in his Entwickelungs- 
geschichte (54 Edition, p. 216—217, Fig. 147). LEoPoLD holds that 
the epithelioid layer is the reflexa, but what has just been said suffices 
I think, to show that this view is untenable. 
That the membrana decidua reflexa should degenerate and dis- 
