. The biology of spiders. Spiders; Insects. 22 THE BIOLOGY OF SPIDERS The underside of the. Fig. 9.—Underside of Abdomen. A, Lung-book ; B, Epigastric furrow ; C, Epigyne ; D, Tracheae ; E, Spin- nerets. omen (Fig. 9) shows more features than the upper. The part next to the pedicle is often more convex than the rest and is called the epigastrium. It is visibly separated from the rest by a groove, the epigastric furrow. The two lung-books, or the two anterior lung-books of the four-lunged spiders, lie in the epigastric region and are conspicuous as paler- coloured patches. The re- productive or
. The biology of spiders. Spiders; Insects. 22 THE BIOLOGY OF SPIDERS The underside of the. Fig. 9.—Underside of Abdomen. A, Lung-book ; B, Epigastric furrow ; C, Epigyne ; D, Tracheae ; E, Spin- nerets. omen (Fig. 9) shows more features than the upper. The part next to the pedicle is often more convex than the rest and is called the epigastrium. It is visibly separated from the rest by a groove, the epigastric furrow. The two lung-books, or the two anterior lung-books of the four-lunged spiders, lie in the epigastric region and are conspicuous as paler- coloured patches. The re- productive organs open be- tween them in the middle of the epigastric furrow. The Reproductive Orifices The vas deferens of male spiders has but a tiny median orifice, very difficult to discern and unprotected by any The oviduct of the female has, however, a larger aperture, in close association with the single or paired openings of the spermathecae which receive and store the spermatophores of the male, the whole surrounded by and forming part of a complex epigynum. This epigynum shows great diversity in form and in external appearance, so that it becomes the surest, and often indeed the only, way of identifying the female of many species of spiders. In its simplest form the epigynum is merely a transverse aperture, but this very primitive type is not common. More frequently an opercular plaque, the scape, surrounds and protects the actual vulva, and of such a type three different degrees of complexity may be recognised. In the first of these there are but two simple apertures on the scape, each leading to a spermatheca. An example of this is shown in Fig. 10. The spermathecal openings, however, may be in a. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Savory, Theodore Horace, 1896-. London : Sidgwick
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Keywords: ., bookcentury1900, bookdecade1920, booksubjecti, booksubjectspiders
