H. T. WHITTELL OX THE DEGENERATION OF HYDATID CYSTS. 49 



What I have just described is the more common form of an early 

 Hydatid cyst. At a later stage of its existence the older cyst 

 becomes filled with smaller ones, which in structm-e and contents 

 exactly resemble the original. These, the so-called daughter- cysts, 

 vary in number in different cases. It is no exaggeration to say that, 

 in some post-mortem examinations at the Adelaide Hospital, I have 

 seen thousands of them turned out from one original cyst. 



Although Hydatids are very destructive of human life if left to 

 take their course, there can be no doubt that the worm itself is not 

 possessed of a high degree of vitality. Both clinical experience and 

 post-mortem examinations lead to this conclusion. A very slight 

 mechanical interference is often sufficient to destroy the worm. In 

 Adelaide we frequently find that a simple puncture with a small 

 hollow needle, and the drawing-off of the fluid contents of the sac 

 through the needle, is all that is required to destroy the parasite, 

 and very few simple cysts resist this mode of attack if repeated two 

 or three times. Even those cysts which are supposed to contain 

 daughter cysts will often perish by degenerative or suppurative 

 changes after the surrounding fluid is withdrawn. 



Having thus paved the way, I may now go on to notice that it 

 frequently happens that, without any interference from the surgeon, 

 the Hydatid dies within the body of its host, instead of passing on 

 through its full course of development. Sometimes this is caused 

 or followed by the formation of an abscess, but perhaps more com- 

 monly the Hydatid undergoes a form of degeneration, and leaves 

 nothing to indicate its former presence but a putty-like substance, 

 which eventually hardens into a gritty, calcareous mass, in which 

 booklets, cholesterine, and other products of degenerative changes 

 may often be found. It is no uncommon thing to find evidence of 

 this degenerative change having taken place in the bodies of patients 

 who have died from other diseases, and in whom there had been 

 during life no symptoms leading to the suspicion of the presence of 

 Hydatids. When this kind of degeneration is in progress, we find 

 that after the operative puncture I have already described, there 

 flows through the needle, instead of the usual clear liquid, a yellow- 

 ish creamy-looking and thicker fluid, which, without microscopical 

 examination, may readily be mistaken for pus. In a later stage of 

 the degeneration, the fluid becomes so thick that it will not flow 

 through a small needle, although a little may often be blown from it 

 on to a slide after its withdrawal. It is to this degenerative change, 

 and particularly to its association with what are supposed to be new. 



