96 MALL. [VoL. XIX. 
Nos. 77 and 334 show what may become of the chorion and 
amnion when they are retained in the uterus long enough. 
The villi are attacked on the outside by leucocytes and syn- 
cytium, the cavity of the amnion collapses, or is penetrated 
and filled, making the mole solid,.as is the case in so many 
younger ova after the embryo and amnion have been de- 
stroyed. 
Another specimen belonging to this group is No. 93. It 
came to the laboratory fresh, enveloped in its decidua, and 
the whole was hardened in formalin. Between the decidua 
and the ovum there is a layer of blood and fibrin. The main 
body of the mole is composed of irregular hypertrophied villi 
with a great amount of blood and syncytium between them. 
Occasionally the syncytial cells are found in the mesoderm of 
the main walls of the chorion. The small cavity within is 
lined with the amnion and is filled with blood. No embryo 
was found. Nos. 159 and 369 are similar specimens, since 
in them the cord is also destroyed entirely. No. 159 is com- 
posed of fragments of a mole, the embryo having been lost. 
However, the fragments are made up of mucous membran2 
of the uterus, large portions of the chorion and some frag- 
ments of the amnion. The mucous membrane is full of small 
abscesses, and leucocytes have invaded the mesoderm of the 
chorion and its villi. The syncytium is very active and at 
numerous points it also has invaded the mesoderm of the 
chorion and villi. The amnion is hyaline, thickened, curled 
upon itself, and at points its epithelial layer has proliferated. 
forming small mounds. 
The specimens just described show the fate e, ova after 
the embryo is destroyed, leaving first the cord and amnion 
and then the amnion alone. Finally the cavity of the amnion 
is punctured, the ovum collapses and the whole is converted 
into a solid mole. Specimens of this kind are rare, since most 
solid. moles are formed from ova in which the amnion and 
embryos were destroyed at a much earlier date. 
