150 ENTOZOA FOUND IN MAN. 



The hydatids which are expectorated whole are 

 generally small, or they may be expelled in frag- 

 ments of variable size, collected into a httle ball ; 

 echinococci, or their hooks, can sometimes be detected 

 amongst these fragments. The expectoration of the 

 contents of the cyst recurs at irregular intervals, 

 usually of several days, and sometimes of several 

 weeks ; when they are discharged in large quantity, 

 urgent symptoms of suffocation, which may even 

 endanger the life of the patient, supervene. 



The extent of the time which is requisite for the 

 expulsion of hydatids from the lungs varies in pro- 

 portion to the size of the cyst, and probably also 

 according to the consistence of its walls ; the expul- 

 sion of the hydatids may occupy a period of many 

 months. 



The physical signs of hydatid tumours of the 

 lungs are evidenced in a ratio to their volume, 

 number, and situation. An enlargement of one or 

 both sides of the chest, and of the intercostal spaces, 

 may be observed, together with displacement of the 

 heart or of the liver, dulness upon percussion over a 

 certain extent of the chest, and absence of the respi- 

 ratory murmur, upon auscultation. The chest is 

 partially deformed, in a manner which is not usual in 

 pleuritic effusion ; and fluctaation may be perceived 

 when the cyst becomes superficial. 



Hydatids of the organs of respiration have been 

 seldom detected unless when they have had some 

 external communication ; and in the majority of the 

 cases which have been recorded, the symptoms were 

 supposed to be due to pleuritic effusion. The long 

 duration of the disorder, the signs of extensive 



