338 MALL. [VoLt. XIX. 
the middle of January. On March 29 she began to bleed 
and aborted on April 19. Apparently her uterus is normal.” 
The unruptured specimen is inclosed in a layer of decidua 
and is covered with villi of unequal size, some being very 
large, as the photograph shows. Within there is a stumpy 
embryo without a neck and with atrophic leg buds. The 
cord is transparent and partly filled with granules, which indi- 
cates that the embryo had been dead for some time before 
the abortion. 
The mesoderm of the chorion and amnion is thickened, of 
even structure, and contains no blood-vessels. In fact, its 
coelomic cavity is entirely obliterated. The main wall of the 
chorion is very thin, often being composed of epithelial cells 
only. The mesoderm of the villi is unusually fibrous and con- 
tains no blood-vessels. The very large villi are degenerated, 
often hollow and do not stain. The syncytium is very deficient 
in quantity; at points it invades the mesoderm. Over the villi 
there is a mass of fibrin and disintegrated blood. Leucocytes 
are not numerous, even in the decidua, which appears to be 
normal. 
The tissues of the embryo are not only dissociated, but also 
macerated, and they do not stain well. The sharp boundaries 
are lacking, showing that adjacent tissues have begun to 
coalesce. In fact, the whole head down to the thorax seems 
to have been converted into a bag in which fragments of car- 
tilage and nerve tissue may be seen. The front of the head 
is adherent to the thorax immediately over the heart. The 
contours of the cartilages, liver, heart and adrenal can be made 
out, but those of the blood-vessels are obscure. 
According to the menstrual history this embryo was in the 
seventh week when bleeding began, which was followed by 
the abortion three weeks later. However, the degree of the 
development of the cartilages and other structures places the 
embryo in the sixth week. The lack of inflammatory reac- 
tion, and the inactivity of the syncytium, suggests that the 
continued bleeding may have been the primary difficulty, 
which was followed by death and degeneration of the embryo. 
