202 MALL. [ VoL. DIEXe 
The ovum is nearly covered with long and well-developed 
villi, having a bare pole on one side. The ccelom contains no 
magma. The embryo is broken from the cord and is macer- 
ated on its ventral end. The head is atrophic; arms and legs 
are normal. At the middle of the umbilical cord there is the 
marked swelling seen in other specimens of this kind. 
Sections of the chorion show the villi to be normal in form 
but somewhat hyaline in structure and without blood-vessels. 
There is a considerable quantity of syncytium. ‘The thick- 
ened umbilical cord has within it a cavity partly filled with a 
reticular substance, homogeneous in appearance, and more in- 
tensely stained than the surrounding tissues. Within the cord 
there are large blood-vessels, greatly distended with blood 
cells, which extend through the walls into the surrounding 
tissues. 
Fic. 137——Photograph of embryo. Natural size. 
Ten millimeters from the attachment of the cord to the 
chorion is the umbilical vesicle. It measures 3 x 2 mm.; 
its walls are all degenerated and its cells, which are necrotic, 
fill its cavity. The stem of the umbilical vesicle reaches but 
half way to the umbilical cord. 
The central nervous system of the embryo is distended and 
dissociated, the spinal cord being segmental to correspond 
with the vertebree. The liver is necrotic and filled with blood. 
The heart is collapsed and dissociated. The large blood-ves- 
sels are collapsed and empty, while the small ones are filled 
with blood. The outlines of abdominal organs are pretty 
sharp, the tissues nearly normal in appearance and fairly free 
from migrating cells. 
Most of the epidermis has fallen off the embryo, but where 
it remains intact it often shows irregular thickening. 
