182 CLASS Y. 
named these pathological products and Hchinococeus also Acéphalo- 
cystes. 
True echinococct propagate themselves by means of cells or vesicles 
within the parent vesicle. This last consists of several concentric, 
thin, albuminous layers ; see Von Sieponp’s figure in Voce Icon. 
Histologie pathologice, Tab. x11. fig. 11. Frequently the worms die 
in the living body and the vesicles are changed into a gelatinous, 
yellow-green mass. 
Comp. RenptorFF de Hydatidibus in corpore humano, presertim in 
cerebro repertis, Berolini, 1822, 8vo.; Kuan Recherches sur les Acéphalo- 
cystes, Mém. de la Soc. d’ Hist. nat. de Strasbourg, 1. 2, (1833); also trans- 
ferred to the Ann. des Sc. nat. Tom. XXIx. pp. 273—300. (The Author 
distinguishes Acephalocystis endogena and A. exogena; some Echinococct 
appeared to multiply themselves by forming new vesicles on the outside of 
the parent vesicles ; such vesicles, he says, occur, especially in the sheep, in 
the lungs and liver ; Von SrzBoupD has not remarked this mode of propaga- 
tion; WieGM. and Ericuson’s Archiv f. Naturgesch. 1845, 2 Bd. s. 241.) 
GuuGE Note sur la structure microscopique des Hydatides, Bullet.. de 
VAcad. royale de Bruxelles, 4 Nov. 1838, Ann. des Se. nat. 2e Série, 
Tom. vill. Zool. pp. 314—317. 
Sp. Lchinococcus erraticus mihi, Echinococcus velerinorum Ruv., Hist. nat. 
Entoz. Tab. Xi. fig. 4, Bremser, Jcon. Helminth. Tas. xviit. figs. 3—13; 
in many domestic animals, especially in their liver. The Hchinococcus 
hominis Rup., is probably not a different species from this. It has been 
met with in the abdominal cavity, in the liver, in the heart, also in the 
voluntary muscles, and in the cavities of the brain (ventriculi cerebré). 
Cenurus Rup. Vesicle single, on which are seated several 
worms, retractile, depressed, rugose. 
Sp. Cenuwrus cerebralis Rup., Hist. nat. Entozoor. Tab. x1. fig. 3, BREMSER, 
Icon. Helminth. Tab. xviii. figs. 1, 2. There is only one species known, 
which occurs in the brain and spinal cord of sheep, occasionally also in 
cattle, in a species of antelope, and according to ROUSSEAU in rabbits. 
The Vertigo of sheep (le towrnis, das Drehen) is a consequence of these 
worms ; the symptoms vary according to the situation occupied by the 
worms ; the general characters of the disease are, that the sheep at first are 
somnolent, then fall into convulsions, run up and down and die of exhaus- 
tion. The vesicles, filled with water, by their expansion compress the 
brain and distend the ventricles, and this sometimes to such an extent, that 
the bones of the skull are affected and become extremely thin. 
Oysticercus Rup. Worm solitary with depressed and roundish 
body passing into a caudal vesicle. Another vesicle external, in- 
cluding the worm. 
Sp. Cysticercus cellulose Rupv., Hydatis jimna BuumMens. Abd. naturhist. 
Gegenstinde, Tab. 39 (copied in Gu&éR. Iconogr. Zooph. Pl. 13, fig. 5), 
