No. 1.] ORIGIN OF HUMAN .MONSTERS. 153 
The sections show that there is a double embryonic vesicle 
composed of the amnion and umbilical vesicle, the walls of 
which are thickened and fibrous, with the embryonic layers 
but poorly defined. The tissues of the vesicle and its cavity 
are well filled with migrating cells. The chorion is also 
fibrous, with blood-vessels and migrating cells extending into 
the villi. The syncytial layer is not extensive. 
No. 14. 
Chorion, 30 mm. in diameter; within them is a small double 
vesicle with a short pedicle 1.5 mm. in diameter. 
From Dr. Friedenwald, Baltimore, 1893. 
Fics. 14a and 14b.—Sections through the nodule (vesicle) of the specimen. 
25 times. A few blood islands as well as an enclosed mass of syn- 
cytium are within the stem, 
