544 Et'hinooooci. 



festecl livers are .soiiietiiiies of enormous size (110 pounds, Ge- 

 rard). The surface shows rounded prominences of various sizes, 

 and there may be a considerable distortion of the organ. If a 

 cyst be cut into, there is a prompt escape of a clear, yelloA\isli 

 serous liquid and a rounded cavity is exposed. The interior of 

 the connective tissue capsule is lined l)y an elastic membrane 

 which is easily detaclied and torn, and tends to roll up. This is 

 the true cyst wall and l)ears on its surface small whitish promi- 

 nences, the brood capsules, and it may also contain several 

 daughter cysts and granddaughter cysts. The liver tissue in 

 the immediate neighborhood is very pale in color, and if nu- 

 merous cysts are present, develops fine but tough strands of 

 connective tissue. In dead cysts there is either a soft and 

 pulpy or a caseous mass in which shreds of the cyst wall can 

 be found. The nature of these shreds can easily l)e recognized 

 microscopically by their laminated structure. Hooklets com- 

 posed of cliitin can also be found in the caseous contents. 

 These facts together with the al)sence of young tubercles in the 

 neighborhood and of lesions in the portal glands, distinguish 

 such lesions from caseous tul)erculous lesions. Echinococci 

 sometimes undergo a purulent degeneration resulting in the 

 production of abscesses. In the contents of such abscesses, 

 fragments of the laminated wall or hooklets can generally be 

 demonstrated. 



The Echinococcus multilocularis forms more tumorlike 

 masses than the E. yjolymorphus, the surface of the former being 

 beset with cysts. On cross section, these bear considerable re- 

 semblance to alveolar or colloid cancers and have the struc- 

 ture already described. Formerly such lesions were consid- 

 ered as cancers. Tlieir true nature was first discovered by 

 Virchow in 1855. 



Similar cysts are more rarely found in the lungs and other 

 organs. 



Pathog^enesis. In spite of the frequency of their occurrence 

 echinococci rarely cause any disturbance of health, even when 

 they are very numerous. Only when the infestation is enor- 

 mous and there are only scattered islands of liver tissue left, 

 do symptoms due to deficiency of bile make their appearance. 

 The greatly enlarged Uver may hinder the movements of the 

 diaphragm and possibly also of the al)dominal viscera, partic- 

 ularly the stomach and intestines. The portal vein may be 

 compressed by echinococci in its immediate neighborhood (Lu- 

 cas). 



Joest's experiments upon animals contradict the view of Monrzon and Schlag- 

 denhauflfen that the liquid contained in the cysts contains a toxalbumen. Ac- 

 cording to Gherardini, in view of the situation of the cysts, any infection pro- 

 duced by their contents must be of a latent character. Griglio found various 

 bacteria in the cyst-contents (streptococci, staphylococci, and bacillus coli). 



