Quarterly Journal Of Microscopical Science Vol 21 Classic Reprint

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ISBN 13 : 9781330459522
Total Pages : 624 pages
Book Rating : 4.4/5 (595 download)

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Download or read book Quarterly Journal of Microscopical Science, 1899, Vol. 41 (Classic Reprint) written by and published by . This book was released on 2015-06-28 with total page 624 pages. Available in PDF, EPUB and Kindle. Book excerpt: Excerpt from Quarterly Journal of Microscopical Science, 1899, Vol. 41 On both sides of the Atlantic, latitude 40 N. marks approximately the southern limit of Arenicola marina. South of this it is replaced in the Mediterranean by A. Claparedii, Lev., and by A. cristata, Stimps., the latter also ranging on the west side of the Atlantic from Cape May (N. J.) to the Caribbean Sea. Its reputed occurrence on the north coast of Alaska (Murdoch), at Vancouver Island (Marenzeller, 1887), Coquimbo, and South Africa requires confirmation. An abundant, widely ranging, and undoubtedly old form such as Arenicola, might be expected to vary considerably in its habits and structure, though it has not hitherto been ascertained how far this is the case. Having paid special attention to this point, we have found that there are (at least on the Lancashire coast) two varieties of A. marina, differing in habits, structure, and times of maturity, and that there is, in addition, considerable individual variability. (1) From high-water mark down to the beginning of the Laminarian zone, the common shore lugworms (or "lugs," as fishermen call them, in contradistinction to the second variety, or "worms") sink their U-shaped burrows to a depth of from one to two feet below the surface. One end of the burrow is marked by a casting, the other by a "countersunk" hole, through which the head of the lugworm is protruded when the tide comes in. The size and colour of the animal vary with the amount of muddy organic matter in the sand. Where there is comparatively little mud, the Arenicola average about seven inches in length and are somewhat transparent, so that the superficial blood-vessels can be clearly seen through the thin body-wall. The gills, which are not very strongly developed, are composed of nine to eleven branches, each provided with three to five pairs of short lateral twigs (Pl. 1, fig. 3). The proboscis and prostomium are only slightly pigmented, and being very vascular, appear red in colour. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works."