Entomology : with special reference to its biological and economic aspects . t, unitedtestes; v, vas deferens.—After Kot-BE. or testes and a pair of ducts {ozidiiets or seminal ducts, respec-tively). Primitively, the ducts open separately, as they stilldo in Ephemeridas, but in nearly all other insects the two ductsenter a common evacuating duct (vagina or ejaculatory duct) ;this opens ordinarily between the penultimate and antepenulti-mate segments of the abdomen, i. usually the ninth andeighth, at any rate never through the last abdominal segment. ANATOMY .\ND PHYSIOLOGY 141 Homologies.—
Entomology : with special reference to its biological and economic aspects . t, unitedtestes; v, vas deferens.—After Kot-BE. or testes and a pair of ducts {ozidiiets or seminal ducts, respec-tively). Primitively, the ducts open separately, as they stilldo in Ephemeridas, but in nearly all other insects the two ductsenter a common evacuating duct (vagina or ejaculatory duct) ;this opens ordinarily between the penultimate and antepenulti-mate segments of the abdomen, i. usually the ninth andeighth, at any rate never through the last abdominal segment. ANATOMY .\ND PHYSIOLOGY 141 Homologies.—As in other animals, the reproductive or-gans are homologons in the two sexes. Thus: Male. Female. Testes = OfariesSeminal ducts ^ OziductsEjaculatory duct =^ Vagina Semi)ial vesicle = Soiiinal receptacleAccessory glands =z Accessory glandsPenis and accessories = Ozipositor Male Organs.—Each testis, though sometimes a singleblind tube, is usually a group of tubes or sacs (Fig. 178),testicular follicles, which open into a seminal duct (zas dcfcr- FiG. 183. Fig. Spermatozoa. A, locustidgrasshopper; S, cockroach,Blatta; C, beetle, Copris.—After BiJTSCHLi and Bal- LOWITZ.
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectentomology, bookyear1
