. American spiders and their spinning work. A natural history of the orbweaving spiders of the United States, with special regard to their industry and habits. Spiders. 38 AMERICAN SPIDERS AND THEIR Spinning Spools. sp Figs. 27,28. View of a spinning spool and spinning spi- got of Epeira di- ademata. (After Meckel.) As many as one hundred and fifty or two hundred may be counted upon the tip of a single spinneret of an Epeiroid spider, as for example, Ar- giopc cophinaria. These spinning spools are two jointed, at least they are divided into two parts, of which the base is the th
. American spiders and their spinning work. A natural history of the orbweaving spiders of the United States, with special regard to their industry and habits. Spiders. 38 AMERICAN SPIDERS AND THEIR Spinning Spools. sp Figs. 27,28. View of a spinning spool and spinning spi- got of Epeira di- ademata. (After Meckel.) As many as one hundred and fifty or two hundred may be counted upon the tip of a single spinneret of an Epeiroid spider, as for example, Ar- giopc cophinaria. These spinning spools are two jointed, at least they are divided into two parts, of which the base is the thicker, and sometimes the longer. They are hollow tubes, through which the delicate ducts connected with the silk glands convey the liquid silk to the surface. These spinning spools are of several sizes and shapes (Fig. 26), and diifer somewhat according to their position upon the several spinnerets. Thus those upon the anterior spinnerets have the basal part (bj) of a conical shape and rather shorter than the point or terminal joint, tj. (Fig. 26 b, c, compare with Fig. 27.) Distributed here and there among these spools of ordi- nary size are a few which are larger and stouter. (Fig. 28.) In Argiope cophinaria there are three of these on each of the middle spinnerets, foiir iipon each of the 2)osterior, and one upon each of the anterior ones. A detailed description of these instruments will be given further on. These groups of spinning spools are surrounded by ranks of hairs and bristles (b, bb, br), both sim2:)le and branched, which are movable and appear to have some important part in spinning. Possibly they serve to direct the course of the threads as they issue from the spools, or it may be that they form a protection to the more delicately organized spinning spools themselves. II. The spinning spools are connected with a system of glands and ducts constituting the internal spinning organs, the reservoir within wliich is formed, and from which is secreted the material for a
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectspiders, bookyear1889
