358 THE ANIMAL PARASITES OF MAN 



Glisson's capsule of the liver and grow into an irregularly shaped 

 formation (chitinous coil), which breaks through the vascular walls 

 and thus forms the alveoli. So far the data coincide well with 

 Leuckart's opinion of the original grape-like form of the Echinococcns 

 multilocularis ; according to Melnikow-Raswedenkow the " granular 

 protoplasmic substance" (parenchymatous layer) is not only present 

 in the interior of the loculi but also outside, and, moreover, "ovoid 

 embryos" are supposed to develop in the chitinous coils, which, 

 " thanks to their amoeboid movements, reach the lumen of a vessel, 

 where, under favourable circumstances, they begin to develop 

 further," that is to say, they become " chitinous cysts with fantastic 

 outlines," or also " single-chambered chitinous cysts " ; scolices may 

 develop in both. Deve, however, considers that these embryos are 

 only prolongations of the protoplasmic layer which secondarily 

 cuticnlarize. 



The multilocular echinococcus, which in man produces a severe disease and 

 almost always leads to premature death, infects most frequently the liver, but may 

 also be found primarily in the brain, the spleen and the suprarenal capsule ; from 

 the liver by means of metastasis it may reach the most various organs, especially 

 those of the abdomen, but also the lungs, the heart, etc. Up to 1902, 235 cases have 

 been described and up to 1906, 265, being 70 from Russia, 56 from Bavaria, 32 from 

 Switzerland, 30 from the Austrian Alps, 25 from Wiirtemberg ; the remaining cases 

 are distributed over Central Germany, Baden, Alsace, France, Upper Italy, North 

 America. In some the origin is doubtful ; in any case after Russia, the mountainous 

 South of Europe is the principal region of distribution. As to the domesticated 

 animals, the same parasite is found principally in the ox (according to Meyer, in 

 Leipzig, in 7 per cent, of the oxen affected with echinococcus) ; it is rarer in the 

 sheep and very scarce in the pig. 



It has already been mentioned above that recently the multilocular 

 echinococcus has been stated to be specifically different from hydatid 

 or unilocular echinococcus. To this may be added the fact that 

 Mangold, who fed a young pig with oncospheres of a Taenia reared 

 from the multilocular echinococcus, found two growths in the liver 

 four months later, which he took to be E. multilocnlaris, and con- 

 sequently one has to assume the existence of two different worms. 

 The chief defender of this view, already put forward by Vogler, 

 Mangold, and Muller, is Possett. He bases his opinions on (i) the 

 more restricted distribution of the multilocular hydatid, the former 

 occurring in districts where only cattle are raised, the latter where 

 sheep-breeding is established ; (2) that those engaged in looking after 

 sheep are attacked by multilocular, whereas those looking after cattle 

 are attacked by unilocular hydatid ; (3) that among the cases of 

 unilocular hydatid occurring in the distribution areas of multilocular 

 hydatid no transitions between the two forms are observed ; (4) on 

 the difference in the hooks both in the hydatid as-well as in the Tcenia 



