Hydatid disease, with special reference to its prevalence in Australia / by John Davies Thomas.

  • Thomas, J. Davies (John Davies), 1844-1893.
Date:
1884
Catalogue details

Licence: Public Domain Mark

Credit: Hydatid disease, with special reference to its prevalence in Australia / by John Davies Thomas. Source: Wellcome Collection.

Provider: This material has been provided by the Francis A. Countway Library of Medicine, through the Medical Heritage Library. The original may be consulted at the Francis A. Countway Library of Medicine, Harvard Medical School.

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    any somatic or visceral cavity, hence their designation of parenchy- matous worms (vers parenchymateux). In such a transverse section, a central and a cortical portion can be distinguished. The former contains the generative, nervous, and water vascular systems; the latter is richly provided with calcareous corpuscles, which are found also—but usually far less abundantly—in the median portion. The Calcareous Corpuscles are rounded oval bodies, measuring 0*019 mm. (1/2,500 inch, Huxley) or less in diameter, which have a very wide dis- tribution in the Tapeworms^ both dur- calcareous'^CorJurcles.0™ After ing their cystic and cestoid phases. Leuckart.) They vary much in size, shape, and number in different Tape- worms, and in the different parts of the same worm. Thus, they may be kidney-shaped, or at times present the stratified appearance of starch granules, or show twin-like or triplet figures, &c. They consist chiefly of carbonate of lime combined with an organic matrix of the same size and appearance as the complete corpuscle. The lime salt can be removed by treatment with acids, and as this usually—but not always—is accompanied by efferves- cence, it may be concluded that the acid combined with the lime is carbonic acid. Yarious views have been held as to the nature and function of these curious bodies—Thus, they were formerly believed to be ova. Yon Siebold regarded them in the light of skeleton structures, Claparede thought they were excretory products, Leuckart is of opinion that these structures may serve, not only as protective and supporting skeleton structures, but probably also to neutralise the action of the acid intestinal juices, which the Tapeworms encounter during their sojourn in the intestines of their hosts. If this were so, it would be difficult to explain why the cystic forms which usually are richest in these corpuscles, should be the very forms actually digested by the juices of the host. Yirchow and Schiefferdecker regard them as derived from connective tissue corpuscles, by a process of partial or complete calcification. Huxley's investigations led him to a somewhat different conclusion.