Infections of the Ovum. Embryo and Fetus 479 



The cystic mole grows slowly and soon fails to maintain 

 the degree of distension of the uterus characteristic of the 

 advancement of pregnancy. Finally its growth becomes 

 halted and its size may continue static for an indefinite 

 period unless the uterine seal is imperfect or becomes de- 

 stroyed. Then its expulsion follows. The expelled cyst 

 commonly shows two unequal parts representing the gravid 

 and non-gravid horns, joined by a narrow, sometimes ne- 

 crotic, isthmus, representing the area contiguous to the os 

 uteri internum. 



Fig. 170 — Desiccated Mole. Cow. 



The embryo had perished at probably thirty days or less ; the sac later 



became necrotic and desiccated. In douching; the uterus 



it was caught in the fenestrum of the catheter. 



More frequently the cystic mole becomes necrotic quite 

 early and undergoes a desiccation similar to the necrosis of 

 the tips of the embryonic sac. The elongated sac collapses, 

 dries and shrivels until it becomes a flattened, wrinkled, 

 yellowish-brown cord. In such case the uterine seal is ab- 

 sent, either having failed to form or, if formed, having been 

 destroyed. Clinically I have seen the desiccated sac protrud- 



