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How We Found the Microzoa.

295

The bands in which the shells occur in the middle sands andgravels bear evidence, too, of current bedding, all of which facts taken together with the presence of southern typos of Mollusca, appear to indicate an inter-glacial period, when the sea was free from floating ice, and the glaciers—if any—ceased to pour into it the mud which formed the lower boulder clay. The partial denudation of the lower boulder clay, however, supplied the materials for the middle sands and gravels, together with the derived Arctic shells—sometimes found mingled with the southern ones in a common tomb. The agency which distributed the shells in the middle sands and gravels I believe, with Mr. De Rance, C.E., F.G.S., to have been marine currents.

All this, and more, came of the preserving of a pinch of sand out of the Saxicava-bored boulder found in the upper boulder clay of Newton-by-Chester.

Anyone wishing for the more detailed results will find them stated in my papers, viz.: In the Quarterly Journal of the Geological Society of Loudon for May, 1874, on "The Discovery of Foraminifera in the Boulder Clays of Cheshire," and in the one for May, 1878, On the Glacial Deposits of West Cheshire, together with Lists of the Fauna found in the Drift of Cheshire and adjoining counties."

Parasites of Man.^[1]

By T. Spencer Cobbold, M.D., F.R.S.

[Continued from page 213.]

Considering the Importance of the new parasite (Flaria Bancrofti) it was thought advisable to devote more space than usual to the literature of the subject; consequently, the remaining species of filariform nematodes may be dismissed with comparative brevity. It happens, moreover, that much doubt hangs over the question of the genuineness of several of the forms that require to be noticed. The human strongholds, on the other hand, are all of them well defined species; and, as will be seen in the sequel, they play almost as important a role in the production of endemic disorders as do the Filaria themselves, In a general sense, the Guinea-worm may be spoken of as a Filaria, but, for reasons given in my introductory treatise and elsewhere, I prefer to consider this parasitic as the type of an osculant genus (Dracunculus,} The nematoids variously placed by helminthologists under the genera Selerostoma, Anchylostoma, Dochmius, and so forth, are all of them closely related to the Strongyli properly so called. As regards the question of nomenclature, I must leave it to Mr. Grove to say whether, in the genera above mentioned, it is permissible for us to retain the final component stoma unaltered. Many continental helminthologists no

↑ Communicated by Mr. Hughes to the Microscopical Section of the Birmingham Natural History and Microscopical Society, October 15th, 1878, On Dr. Cobbold's behalf a microscopic slide was shown, containing numerous embryos of the Guinea worm, The young worms had been mounted some twenty-five years previously. They were originally taken from adult Dracunculusin the possession of the late Sir George Bullingall, of Edinburgh. Altogether the specimens had been preserved for upwards of of a century.

[1] Communicated by Mr. Hughes to the Microscopical Section of the Birmingham Natural History and Microscopical Society, October 15th, 1878, On Dr. Cobbold's behalf a microscopic slide was shown, containing numerous embryos of the Guinea worm, The young worms had been mounted some twenty-five years previously. They were originally taken from adult Dracunculusin the possession of the late Sir George Bullingall, of Edinburgh. Altogether the specimens had been preserved for upwards of of a century.

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