ECHINOCOCCUS SCOLICIPAKIENS. 201 



In general the contents of the fresh and vigorous living 

 vesicle are the ordinary, limpid, proteinaceous fluid, which 

 in the Echinococci contains also succinic acid ; T and after 

 death the same phenomena occur in it as in that of the 

 Cysticerci, namely, turbidity, pus-formation as it is usually 

 called, fatty degeneration, and calcification, which, however, as 

 follows from the results described, go on, not between the enve- 

 loping cyst and the Echinococcus, but within the Echinococcus 

 itself. As regards the statement that a formation of pus takes place 

 in the interior of the Echinococcus-\ 7 esic\es, I will not directly 

 deny the possibility of such an occurrence; but I do not exactly 

 see how the process of pus-formation can go on with the en- 

 capsuled fluid, enclosed by an Echinococcus. The ovarian cysts 

 can certainly not be brought in here as analogous cases, in 

 which these processes take place, as in these we have to do with 

 the tissues of the human body, but here with a fluid separated 

 from the human body by a worm. If we examine the purulent 

 mass in the cysts of Cysticerci, we certainly find a quantity 

 of large granulated corpuscles, resembling pus-corpuscles, and 

 smaller molecular granules. And this is no wonder, as the worm 

 not firmly connected with its enveloping membrane, and this has 

 the power and opportunity to act on a great part, like the in- 

 flamed inner wall of a pus-forming ovarian cyst. I have no 

 experience of Echinococci in the human subject, but we find 

 authors speaking of purulent Echinococci in every text- book. 



1 The detection of succinic acid, which, as is well known, is produced, amongst other 

 ways, by the action of nitric acid upon fat or fatty acids, and is also formed in the 

 spontaneous decomposition of certain organic substances in the presence of much water, 

 is best effected, according to Heintz ('Lehrbuch der Zoochemie/ p. 239), in the 

 following way : The fluid of the Echinococcus is evaporated ; the syrupous extract is 

 mixed with a little muriatic acid, and repeatedly agitated with water and ether, free 

 from alcohol, until the ether can take up nothing more. On the evaporation of the 

 etherial solutions impure succinic acid remains. This is purified by dissolving it in 

 water, evaporating the filtered solution, washing the residue with cold alcohol, and 

 repeated recrystallization from the alcoholic solution. Succinic acid may also be 

 detected in other animal substances in this way unless hippuric or benzoic acid be 

 present at the same time, in which case some precautions would have to be employed, 

 which will be found in Heintz, 1. c., p. 232. 



When we consider how easily a great many organic lime and potash salts, which are 

 readily converted into carbonates, become transformed into succinates, we are, perhaps, 

 justified in thinking that a part of those calcareous corpuscles of the Cestodea, and 

 especially of the Echinococci, which do not effervesce when dissolved in acids, may 

 contain succinic acid instead of carbonic acid. 



