626 VARIOUS FORMS OF ECHINOCOCCUS. 



Our knowledge of the primary position of the Echinococcus is 

 upon the whole so scanty, that we are far from being able to 

 utilise the differences in its occurrence for the explanation of the 

 different forms of Echinococcus. In pigs the Echinococcus of the liver 

 lies, as we have already mentioned, originally in the interlobular 

 spaces ; but whether in the lymphatics, bile-ducts, or blood-vessels, 

 which together form this capillary network, cannot be determined. 

 For my own part, I am most inclined to place the primary seat of the 

 Echinococcus in the blood-vessels, and I can at least urge in favour of 

 this opinion the analogy of Cysticercus pisiformis and C. tenuicollis, 

 and perhaps also the wide distribution of the Echinococcus itself. Vir- 

 chow, on the contrary, thinks that the multilocular Echinococcus 

 develops in the lymphatics, while Schroder van der Kolk, 1 Friedreich, 

 and Morin are convinced that it really originates in the gall-ducts. 



My own acquaintance with the multilocular Echinococcus is based 

 on the investigation of some preserved specimens. Not only had 

 Professor Luschka the kindness to place at my disposal portions of 

 two tumours investigated by von Zeller and himself, 2 but I was also so 

 fortunate as to find an entire (though of course extracted) tumour in 

 v. Sommering's collection, which now belongs to the Giessen Uni- 

 versity Museum. 3 The latter, which is about the size of a duck's 

 egg, is flattened at one end, and has there a cavity of the size of a nut, 

 with walls irregularly eroded. This cavity unquestionably represents 

 the ulcerated cavity found quite constantly in specimens of Echino- 

 coccus multilocularis at a certain stage of development. As may be 

 seen from the above description, the Echinococcus-lA&ddeTS are on an 

 average larger than in the two other cases known to me, but otherwise 

 they perfectly correspond with them. 



The nature of the material at my disposal has rendered it impos- 

 sible for me to add anything new to the earlier observations, and 

 particularly to the statements of Zeller and Virchow. Thus all that 

 I can offer hardly amounts to anything more than a confirmation of 

 what is already known. More recent observations 4 have in fact done 

 but little to advance our knowledge of the Echinococcus multilocularis. 



The size of the cavities, and of the Echinococcus-\Aa,ddeTS which 



1 Ruyssenaers, " De nephritidis et lithogenesis quibusdam momentis," Dissert, inaug., 

 Traj. ad Rhen., p. 49, 1844 (cited by Virchow). 



8 See Virchow' s Archiv f. pathd. Anat., Bd. x., p. 206. 



8 In the catalogue of this collection, numbered 215, with the note "Tumor hepatis 

 viri, similis Baillie Fasc. v., PL iii., Fig. 3." 



4 See especially the statements of Friedreich (Archivf. pathol. Anat., Bd. xxxiii., 1865), 

 of Klebs (Handb. d. pathd. Anat., Bd. ii., p. 511, 1869), and of Marie Prougeansky, 

 ( " Ueber die multiloculare ulcerirende Echinococcusgeschwulst in der Leber," Inaugural- 

 Dissert., Zurich, 1873), and Morin (loc. cit.). 



