No. 1.] ORIGIN OF HUMAN MONSTERS. 355 
Fic. 379.—Section of a portion of a villus. >< 250 times. The synctium, 
S, is invading the mesoderm of the villus. 
No internal structures could be seen and in handling the 
embryo it fell into pieces. No doubt the embryo had been 
dead for some time. 
Sections show that the mesoderm of the umbilical cord, 
main wall of the chorion and the villi are fibrous, with a 
curious growth of the blood-vessels in some places. Within 
them there are numerous fragmented cells, which may have 
come from the blood of the embryo. The syncytium is very 
extensive, necrotic at points and is not infiltrated with leuco- 
cytes. In many places it dips deep into the mesoderm of the 
villi and forms islands of epithelial nests. The wall of the 
amnion is composed of two layers of cells and appears to be 
normal. 
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