274 ENTOZOA. 



growtli, as tliey are given (chiefly from Yircliow and Luschka) in 

 Lankester's edition of Kliclienmeister's well-known manual. As I 

 have not yet had any opportunity of verifying the descriptions of 

 these authors, I shall supplement them with the condensed account 

 of this growth, as given by Leuckart, from the cases by Zeller and 

 Virchow ("Die menschl. Par.," s. 370) : " Hitherto we know this 

 growth only from the liver, in which it forms a firm, solid, and 

 tolerably rounded mass of the size of the fist or even of a child's 

 head. At first sight, it looks more like a pseudoplasm than a 

 living animal parasite. If you cut through the tumour, you recog- 

 nize in its interior numerous small caverns, mostly of irregular 

 shape, and separated from one another by bundles of connective 

 tissue, more or less thick, and including a tolerably transparent 

 jelly-like substance. In the intervening stroma, a blood-vessel or 

 a collapsed bile-duct runs here and there ; but there is nowhere any 

 trace of true liver substance. The outer boundaries of the tumour 

 are in most cases pretty well defined, so that the attempt to cut 

 these growths out is not difficult. In particular spots, especially 

 at the surface, one sometimes sees white, moniliform, jointed lines 

 passing off from the tumour, and even thicker terminations which, 

 perhaps, expand in the neighbouring liver-parenchyme into new 

 (multilocular) groups of different size. In one case, recorded by 

 Yirchow, the growth extended, together with Grlisson's capsule, a 

 long way towards the intestine." To this description it may be 

 added, that the growth on section presents an appearance not alto- 

 gether unlike alveolar colloid, having, in point of fact, been con- 

 founded vnth that pathological product, with which, however, as 

 stated by Yirchow, it has nothing in common. This is proved not 

 only by the occurrence of the pathological features above mentioned, 

 but also, more particularly, by the well-ascertained presence of 

 echinococcus heads in most of the so-called alveoli. Many hypo- 

 theses have been broached with the view of explaining the mode in 

 which these multilocular hydatid growths are formed. I have 

 neither space nor inclination to discuss the question fully, but I 



