Male genital system of adult Pholcus phalangioides (one day after final molt). (a): Longitudinal section of the male genital system. The convoluted vas deferens possesses a thin tube-like shape. Within the testis the different stages of spermatogenesis, spermatogonia (dark) and later stages of spermatogenesis near the center (bright) are clearly visible. (b): Transition between testis and vas deferens. The thin vas deferens is filled with spermatozoa and different kinds of secretion (c.f. Fig. 6). (c): Section of the testis. The lumen is very wide and contains different secretions. Note the secretion droplets (asterisk) and the different cysts of spermatids. (d): Near the genital opening the vasa deferentia fuse to form the ductus ejaculatorius which accumulates large amounts of seminal fluid. (e): Longitudinal section through the genital opening, bordered by the cuticle. The epiandrous apparatus is located in front of the genital opening. Note the epiandrous gland and its secretion within the spigot. De, ductus ejaculatorius; Eg, epiandrous gland; Esp, epiandrous spigot; Go, genital opening; Mg, midgut gland; Sg, silk gland; Sp, spermatids; Te, testis; Vd, vas deferens.