Smithsonian miscellaneous collections . ucture as the onychophorannephridia, suggesting that they have had a common origin with thelatter, though they have, lost the vibratile cilia still retained in thenephridial canals of the Onychophora. Finally, the reproductivesystem of the Onychophora is decidedly arthropodan in its structure,since the germaria (equivalent to the gonads of Annelida) areenclosed in gonadial sacs derived from the coelomic walls, and thegametes are discharged through gonoducts formed from a pair ofcoelomic sacs and their outlets. The structure of the nephridial andgenital o
Smithsonian miscellaneous collections . ucture as the onychophorannephridia, suggesting that they have had a common origin with thelatter, though they have, lost the vibratile cilia still retained in thenephridial canals of the Onychophora. Finally, the reproductivesystem of the Onychophora is decidedly arthropodan in its structure,since the germaria (equivalent to the gonads of Annelida) areenclosed in gonadial sacs derived from the coelomic walls, and thegametes are discharged through gonoducts formed from a pair ofcoelomic sacs and their outlets. The structure of the nephridial andgenital organs in the Onychophora and Arthropoda is, of course, a NO. 14 INSECT ABDOMEN SNODGRASS necessary result of the general obliteration of the coelomic walls, andtherefore might be supposed to be an independent development ineach case. The testes of Onychophora lie dorsally in the posterior part of thebody; they are tubular in form (fig. 5 C, D, Tes) but vary in lengthin different species. Each discharges immediately into a saclike semi-. FiG. 5.—Onychophora : internal reproductive organs. A, Peripatoides novae-zealandiae, female organs, dorsal view. B, same, ovarialend of oviduct with spermathecal and other diverticula. C, Peripatus tholloni,male organs (from Bouvier, 1905, with parts separated for clearness). D, Peri-patapsis blaiftvillei, organs (from Bouvier, 1902, with accessories omitted).E, same, spermatophore (irom Bouvier, 1902). a, b, diverticula of oviduct; AcGld, accessory genital gland; Dej, ductusejaculatorius; Epdm, epididymis; Lg, ovarial ligament; Od, oviduct; Ov, ovary;Sphr, spermatophore; Spt, spermatheca; Tes, testis; Utrs, uterus; Id, vasdeferens; Vsrn, vesicula seminalis. nal vesicle (Vsm) with muscular walls, within which the spermatozoaare matured. The slender vasa deferentia (Vd) proceeding from thevesiculae are much convoluted and the upper part of each usuallyforms an epididymislike mass of closely entangled coils (Epdm). Theductus ejaculatorius
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