. 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. 310 AMERICAN SPIDERS AND THEIR SPINNINGWORK. Several illustrations of the types of hairs known as auditory are here reproduced from the latter writer. Their character is well enough ex- plained in the legends of the cuts, but a brief description may be added. The two parts of the hairs are distinguished as the root and the stalk or shaft. By the root is understood that portion which enters the cuticle, and is inserted into an a
. 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. 310 AMERICAN SPIDERS AND THEIR SPINNINGWORK. Several illustrations of the types of hairs known as auditory are here reproduced from the latter writer. Their character is well enough ex- plained in the legends of the cuts, but a brief description may be added. The two parts of the hairs are distinguished as the root and the stalk or shaft. By the root is understood that portion which enters the cuticle, and is inserted into an appropriate pit; by the stalk the free part of the hair which extends above tlie cuticle. The hairs of spiders, both by their structure and their root, appear to be divided into two principal types, perfectly distinct. One sort is distinguished by a root which is much larger than the portion of the stalk im- mediately above it. In other words, the stalk narrows at its foot to swell out again into a much enlarged root, thick- ened into the form of a button and in- serted into a sac like cavity of the skin. (See Fig. 294.) This is what Wagner denominates a Tactile hair, proper. The roots of the other sorts of hair are ordi- narily much smaller, as compared with their stalks, than the type above named. (See Figs. 295 and 297, r, r, compared with Fig. 294, r, r.) The hair pits or follicles enclosing the roots are also more simply constructed. Tactile hairs (poils tactilcs) are en- dowed with extreme sensibility, as is manifest from the fact that the lightest filament of silk can at once be detected by them and communicated to the ani- mal. The other types are simpler in their structure and, perhaps, their func- tion. Dahl does not make any distinc- tion between the hairs of the different types, and names them all auditory; but Wagner distinguishes the hairs into three principal types, the Tactile hair, including one of finer structure (poll tactil fin), the Beaded hair (poll a chape
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectspiders, bookyear1889
