Eleven miscellaneous papers on animal parasites / [Ch. Wardell Stiles and others].

Date:
1902
Catalogue details

Licence: In copyright

Credit: Eleven miscellaneous papers on animal parasites / [Ch. Wardell Stiles and others]. Source: Wellcome Collection.

Provider: This material has been provided by London School of Hygiene & Tropical Medicine Library & Archives Service. The original may be consulted at London School of Hygiene & Tropical Medicine Library & Archives Service.

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    It may be noticed, first, that this description is scarcely detailed enough to enable the certain recognition of the parasite. If another case occurred in which raonostomes were found in the lens, one would be justified in considering them identical with von Nordmann's form, chiefly on the ground that it would scarcely be possiljle to prove that they were ditt'erent. Under these circumstances it need not be thought strange that authors have resorted to more or less speculation in order to interpret this case. It may also be noticed that while later authors have universally attributed the name Monostoma lentis to von Nord- mann (1833), this author apparently did not use the binomial in ques- tion. It would appear, on the contrary, that Gescheidt (1833, p. 421) was the proposer of the name. Diesing (1860, p. 329) thinks that the worms mentioned by Ammon (1843) as ''Distoma ocuU /mmwii may be identical with Monostoma lentis, an opinion more or less concurred in by Weinland (1859, p. 80), Cobbold (1876, p. 211), and others. While this view can not be desig- nated as impossible, it should be recalled that the figures and description of oculi kmumV (see p. 29) distinctly prove the presence of two suckers; hence, if Diesing is correct, Monostoma lentis would have to be considered a distome {^Aqamodistomimi^, as Ktichenmeister (1855, pp. 180-182) has already pointed out, and not '•^Distoma oculi humani^'' a member of the genus Monostoma. Against considering Monostoma lentis an Agamodistomum, the point may be advanced, as already recog- nized by Leuckart (1863), that Nordmanu had the opportunity of exam- ining the fresh material, and since he was an exceedingly careful observer, it would not appear unreasonable to assume that he would have discovered the ventral acetabulum had one been present. Too much weight, however, should not be attached to this argument, since it has not infrequently occurred that ventral acetabula have escaped the attention of even careful observers. Kiichenmeister (1855, pp. 180-182) endeavored to settle the questions involved by a reexamina- tion of the original specimens, but this, unfortunately, was not possi- ble, since they could not be found. He suggests the possibilit}^ that the organism in reality represents a young Cysticet'cus celhdosae, and refers to the possibility of mistaking young specimens of Cysticercios pisiformis, of the rabbit, for trematodes. Monostoma leporis has, as a matter of fact, been shown by Railliet (1890) to be Cysticercus j)isi- fonriis. Later (1882, p. 285) Kiichenmeister gave up this idea and he looked upon the parasite as resulting from a proliferating redia, the capsule of which might have escaped the attention of Jiingken. Leuckart (1863, pp. 526, 633-634) is inclined to doubt Kiichenmeister's view of the cysticereal nature of Monostom,a lentis. He says: My observationg on the development of this parasite \_Q\j?iic.erc!v^ cellulosie] are only slightly favorable to this hypothesis. Not only that the young bladder worms origi- M(!ine Beobacihtungen iiber die Entwicklnng dieses Schmarotzers sind dieser Hypothese nur wenig gi'instig. Nicrlit, IiIoh, duss die juiigeii Finneii anl'angs oine