Smithsonian miscellaneous collections . cealed in adeep genital chamber above the long ninth abdominal sternum. Theirbases arise close together (fig. 27 A) from the anterior wall of thegenital chamber {-v-x) where they are united upon a common apode-mal plate {Ap) extending forward. Each penis {Pen) consists of abasal stalk bearing two distal lobes, and is traversed by a ductusejaculatorius (Dej). The median lobe (a) is the true terminus of thepenis and contains an eversible end-sac (preputial sac, c), into whichthe ejaculatory duct discharges; the lateral lobe (b) is an accessoryprocess, or p
Smithsonian miscellaneous collections . cealed in adeep genital chamber above the long ninth abdominal sternum. Theirbases arise close together (fig. 27 A) from the anterior wall of thegenital chamber {-v-x) where they are united upon a common apode-mal plate {Ap) extending forward. Each penis {Pen) consists of abasal stalk bearing two distal lobes, and is traversed by a ductusejaculatorius (Dej). The median lobe (a) is the true terminus of thepenis and contains an eversible end-sac (preputial sac, c), into whichthe ejaculatory duct discharges; the lateral lobe (b) is an accessoryprocess, or paramere, of the penis. A long slender rod, or virga,usually accompanies each ejaculatory duct, its apical part being pro- NO. 14 INSECT ABDOMEN SNODGRASS 79 tracted with the eversion of the end-sac. The ductus ejaculatorii,though independent for some distance before entering the penes, areunited anteriorly in a ductus conjunctus (Dejcn), which takes itsorigin in a sachke seminal reservoir (rs) that receives the two vasadeferentia (Vd).. Fig. 27.—Hexapoda-Dermaptera: three types of structure in the male genitalexit system and the intromittent organ. (Diagrams based on Meinert, 1864,1868; Jordan, 1909; Heymons, 1912; Walker, 1922; Snodgrass, 1935.) A, Labiduroidca, penes separate beyond common basal apodeme. B, Hcmi-mcrus talpoides, penes united, but both exit ducts retained. C, Forficuloidea,penes united, only one functional duct. a, median lobe of penis; aa, median lobe of conjoined penes; Ap, basalapodemal plate of penes or penis; b, paramere lobe of penis; c, eversible end-sac of penis: cc, end-sac of conjoined penes; Dcj, ductus ejaculatorius; dej,nonfunctional branch of ejaculatory duct; Dejcn, ductus ejaculatorius conjunctus ;Pen, penis; rs, seminal reservoir; Vd, vas deferens; Vdcn, vas deferens con-junctum; Vsm, vesicula seminalis; x-x, anterior wall of genital chamber. In Hemimcnis and Forficuloidea the penis is a single structure(fig. 27 B, C), but, since it is armed
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Keywords: ., bookcentury1800, bookdecade1860, bookidsmiths, booksubjectscience
