616 VARIOUS FORMS OF ECHINOCOCCUS. 



The form of Echinococcus whose proliferation I have here described 

 is that which Kiichenmeister formerly maintained to be the repre- 

 sentative of a distinct species E. scolecipariens. The name is not 

 very distinctive, since the other forms of Echinococcus also produce 

 scoleces. It might have been more appositely called E. granulosus or 

 simplex, if one do not prefer Kuhn's designation of " exogenous " 

 Echinococcus. After our previous discussion, we need not repeat that 

 it does not represent any distinct species. 



This simple Echinococcus is specially frequent in domestic 

 mammals, particularly in the pig, which, in this country, is the 

 animal most infested with Echinococcus. But even in man it is not 

 a rarity. Kiichenmeister, in the first edition of his "Parasiten," 

 recounts, it is true, only two cases one observed by Gescheid 

 (Echinococcus of the eye), and another by Eschricht (Echinococcus in 

 the liver, from Iceland, usually compound) ; but a very superficial 

 review of the numerous cases of Echinococcus now reported is sufficient 

 greatly to increase the number. x The case of Eschricht is further of 

 importance, inasmuch as he was one of the first expressly to mention 

 the head in the simple Echinococcus occurring in man. 



Generally the Echinococcus granulosus occurs in the omentum under 

 the peritoneal covering of the abdominal wall and in the bones, but 

 there are also instances of its occurrence in other organs, especially 

 the liver, spleen, lungs, which attract our attention all the more 

 readily since the worm in these places usually grows to a considerable 

 size. We must, therefore, note expressly that the simple Echinococcus 

 is not the only form which the above organs harbour ; indeed, another 

 form is very frequently found, which is characterised by the possession 

 of daughter-bladders internally. In the lungs and liver this com- 

 pound Echinococc-iis is actually much more frequent than is the simple 

 one, which does not, of course, exclude the possibility of their occa- 

 sional occurrence together in the same body, and often close beside 

 one another. 2 



This second compound form of Echinococcus is that which Kiichen- 

 meister designated E. altricipariens, a name which has now fallen into 

 disuse, and may very suitably be replaced by the name E. hydatidosus 

 (Echinococcus endogena of Kuhn). 



This Echinococcus hydatidosus is distinguished from the above- 



1 Somraerbrodt, who has collected the cases of E. granulosus occurring in man 

 (Archiv f. pathol. Anat., Bd. xxxvi., p. 272), estimates them at seventeen, but this 

 number has been tripled by Becker, Neisser, and Helm. 



8 Specially instructive is a case observed by Haen (quoted by Davaine, loc. cit., p. 

 367), where simple and hydatiform -fic&inococeus-bladders occurred in the liver of the same 

 individual. Similar cases are also reported by Wunderlich (Archiv f. physiol. Heilkunde, 

 p. 283, 1858), by Davaine (Mtm. Soc. biol., p. 106, 1857), and by Helm (loc. cit., p. 148). 



