158 



CHAPTER XII. 

 HYDATIDS ECHINOCOCCI OF THE LIVER. 



SYNONYMOUSLY. Hydatids are known as the Hydatis of 

 Laennec, and derived from the Greek vSanc, a vesicle, 

 from vSup water; Acephalocystis,from a privative, c60aX} 

 the head, and fct/<m? a vesicle simply a vesicle 

 without a head ; the //w adherence of Cruveil- 



hier ; the Kchinococcus Ilominis of Uudolphi and 

 I'.remser; tlie I'olycephalus lliuniinus of Zeder; the 



Fisrhiosoma nf I'.ivra. 



NATIONALLY. The Ilydatide of the French; tin- 

 Wasserblasse, IJlasenwiirm of the G : ;. tilde 



of the Italians, and the Hy.iatid of the Kuglish. 



HISTORICALLY. Physicians at a very remote period 

 were undoubtedly familiar with large cysts of the liver, 

 tilled with an aqueous fluid, but were i^nm-ant of their 

 real nature. Hippocrates, A.I). 450, in his f>r>th Aphorism 

 (section vii.), gives the following: 44 When the liver is 

 filled with water and hursts into tlie epiploon, in this 

 case the belly is filled with water and the patient 

 Galen, some two centuries afterwards, understood this 

 case to refer to Hydatids <>f the liv.-r, hut iinds difliculty 

 in explaining how they could burst into the epiploon 

 unless by ulceration. It would si :.-n, that 



our author meant the cavity of the peritoneum. 

 Hartinann, in 1685, directed attention to their being of 

 an animalcular nature. Tyson, in IfJ'Jl, endeavour. 

 prove that they were a species of worms, or imperfect 



