164 ENTOZOA FOUND IN MAN. 



this so far as the uterus is concerned. It is also very- 

 rare, owing to the nature of the walls of the pelvis, 

 for a hydatid cyst to open externally. 



The relative depth at which the cyst is situated 

 is the principal circumstance which modifies the 

 severity and time of appearance of the complications 

 produced by its growth ; and the extent of the 

 adhesions which it forms, and which prevent its 

 rising towards the abdominal cavity, is also not 

 without some influence upon the symptoms. 



Hydatids in the pelvis could scarcely be mistaken 

 for abscess in that region ; they might more readily be 

 confounded, in the female, with a sanguineous tumour, 

 but the formation of the latter is ordinarily accom- 

 panied by general indisposition, by menstrual de- 

 rangements, and by pains, which is increased upon 

 pressure, in the lower part of the abdomen. 



Fibrous and cancerous tumours may be distin- 

 guished by their consistence, from hydatids, and, in 

 the case of cancerous tumours, by the peculiar 

 cachexia also. 



In the majority of cases, an exploratory puncture 

 will be necessary to establish the diagnosis ; the dis- 

 charge of the hydatid liquid, and of the booklets of 

 the echinococci, or of some portion of the vesicular 

 worm, would, of course, at once decide the character 

 of the affection. 



When the cyst has reached a large size, it may 

 cause a projection above the pubis, and be recognised 

 by means of palpation and percussion ; and, at the 

 same time, a rectal or vaginal examination may lead 

 to the discovery of a smooth, round, and painless 

 tumour in the pelvic cavity. 



