HELMINTHOLOGY-HELMINTHES CYSTICI.

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as a distinct new species of Cyst-worm, Cysticercus pedun-culatus; in which certainly no one will follow him.

[The full account of Mr. E. Wilson’s researches respectingthe Echinococcus appears in the Transactions of the RoyalMed. and Chirurg. Society of London , Nov. 12, 1844 (vol.xxviii, p. 21, pi. 1), “ On the Classification, Structure, andDevelopment of the Echinococcus hominis, showing reasonsfor regarding it as a species of Cysticercus.” He regardsthe transparent oviform bodies as “ apparently adipose cells,”and seems to consider them as peculiar to individuals thathad been some time dead; both which suppositions areundoubtedly erroneous, as is also the statement that thesebodies are scattered irregularly through the substance of theanimal, for they are always situated immediately under theintegument, or between it and the internal granular substanceof which the interior of the body is chiefly composed. Hisaccount of the mode of development of the animalcules ishighly interesting, if confirmed by further observation. Thecomparison of the animalcule with the genus Cysticercus(Zeder) was made by Pallas as far hack as 1766, and in1800 Zeder makes it a species of Cysticercus. Laennec in1804 describes the granulations which he observed adherenton the walls of the cyst as composed of several individualvermiculi, which, he says, nearly resemble the Cysticercus.Under the modern arrangement, however, of these genera,as defined by Rudolphi, the Echinococcus must constitute adistinct genus.] [On the same subject is also a paper bythe Translator in theTransactions of the Microscopical Societyof London, November 13, 1844 (vol. ii, P. i, p. 10, pi. 1),“ Some Observations on the Natural History of the Echi-nococcus,” in which is given a short summary of the historyof this animalcule, and an attempt is made to show theunity of the species in man and other animals, and especiallyto indicate the mode of attachment of the Echinococci amongthemselves, and of the aggregate masses or so-called granu-lations to the interior of the parent-cyst, together with otherparticulars relating to the intimate structure of thesecreatures.]