360 MALL. [Vor. XIX. 
The external form looks much like that of a chick. Sec- 
tions show that the tissues are generally dissociated and also 
macerated. 
No. 400. 
Embryo, 3.5 mm. long. 
Dr. Kaumheimer, Milwaukee, Wis. Bardeen Collection. 
“Last menstruation October 21; abortion December 19. 
Placed in 10 per cent formalin an hour after the abortion.” 
The external form is that of a normal embryo, but the 
sections show that marked pathological changes have taken 
place. The central nervous system is distended and partly 
Fic. 400—Drawing of the embryo. X 8 times. 
filled with round cells. The walls of the brain of the embryo 
are dissociated and apparently are giving rise to the numer- 
ous round and fragmented cells which are present. The heart 
and large blood-vessels are distended and well filled with 
blood. The tissues of the mesoderm are generally filled with 
round cells as well as with numerous fragmented nuclei, the 
infiltration including the myotomes and the peritoneal cavity. 
The amnion and epidermis are intact. 
No. 401. 
Embryo, 5.5 mm. long. 
Dr. Hay. Bardeen Collection. 
Much of the chorion and many of the villi and the syn- 
cytium are necrotic and infiltrated with many leucocytes. The 
tissues of the embryo are dissociated, macerated and infiltrated 
