214 MALL. [Vor. XTX. 
20 x 20 mm. On one side there is a small atrophic embryo 
2.5 mm. long. 
The sections of the chorion show that its villi are. well 
formed and are imbedded in a mass of blood from the mother. 
Possibly the syncytial layer of epithelium is increased. The 
coelom side of the chorion is smooth and is in contact with 
the amnion. Attached to the amnion there is the embryonic 
mass or remnant which does not reach to the chorion; there is 
no umbilical vesicle to be found. The amnion and embryo 
are completely separated from the chorion. There are no 
blood-vessels in the chorion. 
The embryo is cylindrical in form, being attached through- 
out half of its length to the amnion and passing through it. 
In the center of the embryo there is a solid column of cells 
quite sharply defined—the remnants of the central nervous 
system. At the tail end of the embryo there is a blind tube, 
the allantois. The ccelom of the embryo, which is as a pocket 
on its ventral side, contains an irregular sac which may be 
either the heart or the umbilical vesicle; probably the former. 
No. 174. 
Ovum, 35 x 25 x 25 mm.; embryo, 13 mm. long. 
Dr. Gibbs, Baltimore. 
Last period January 11, 1900; bleeding five weeks later, 
which continued until the eighth week, when the abortion fol- 
lowed. The ovum is smooth, having but few villi, and is 
filled with a granular magma. 
Sections of the chorion show a marked degeneration of its 
walls, nearly all of its villi having been destroyed. Those few 
Fic. 174.—Embryo lying on piece of the chorion. Enlarged 2 diameters. 
