168 ENTOZOA FOUND IN MAN. 



grave than that of renal tumours formed as a con- 

 sequence of pyelitis. The hydatid cysts of the 

 kidney have, like those which are developed in other 

 organs, a great tendency to perforation, and to con- 

 traction after they have been completely emptied of 

 their contents ; so that the cases of recovery after 

 the evacuation of the hydatids through the urinary 

 passages, are not very rare, but it cannot be previ- 

 ously determined, in any given case, whether such a 

 complete discharge of the contents of the cyst will 

 take place, or not. 



Chapter XXIV. 



HYDATIDS SITUATED IN THE SUPEEFICIAL PARTS 

 OF THE BODY AND IN THE BONES. 



Hydatids are very seldom developed in the super- 

 ficial parts of the body, and more rarely still in the 

 extremities ; they are equally infrequent in the 

 organs which are placed superficially, such as those 

 of the face, and the external organs of generation. 



Dr. Davaine gives an account of about forty cases 

 which he has collected from various sources. Of 

 these, eight occurred in the orbit, one in the lachrymal 

 gland, and one in the eyelid ; two cases are recorded 

 of hydatid cysts in the canine fossa, one m the lower 

 jaw, and one in the tonsil ; seven cases, of which 

 three appear to have been connected with the thyroid 

 gland, were observed in different parts of the neck ; 

 thirteen occurred in the parietes of the body, and 



