. Elementary text-book of zoology, general part and special part: protozoa to insecta. Animals. GENERATIVE ORGANS. 641. fliience of the secretion of iin accessory gland. Beneath the recepta- culum seininis, a hvrge pouch-like diverticulum, the bursa copulatrix, which assumes the function of the vagina, is sometimes separated from the vagina. In the butterflies (fig. 448) a narrow duct serves to convey the sperm from this bui-sa, which opens separately, to the receptaculum. The male generative organs consist of paired testes and their vasa deferentia, of a common ductus ejaculatorius and of the
. Elementary text-book of zoology, general part and special part: protozoa to insecta. Animals. GENERATIVE ORGANS. 641. fliience of the secretion of iin accessory gland. Beneath the recepta- culum seininis, a hvrge pouch-like diverticulum, the bursa copulatrix, which assumes the function of the vagina, is sometimes separated from the vagina. In the butterflies (fig. 448) a narrow duct serves to convey the sperm from this bui-sa, which opens separately, to the receptaculum. The male generative organs consist of paired testes and their vasa deferentia, of a common ductus ejaculatorius and of the external copulatory organ {fig. 450). The testes are long blind tubes, which are present either singly or in number on either side, and are often coiled together so as to form a seemingly compact brightly-coloured body. They may also be united to foi-m an unpaired organ in the middle line. The testicular tubes are prolonged on either side into a usually coiled efferent duct or vas deferens, the lower end of which dilates considerably, and may even swell out to the form of a vesicle (vesicula seminalis). At the point where the two vasa deferentia join to form the muscular ductus ejaculatorius, one or more glandular tubes often pour their coagulable secretion into the latter; the secretion serving to form a case The transference of the spermato- phores into the body of the female is effected by a horny tube or groove which surrounds the end of the ductus ejaculatorius. This tube, when not in use, usually lies retracted in the abdomen, and when protruded is suri-ounded by external organs for attachment (valves or pincers), as by a sheath. In exceptional cases {Lihellula) the copulatory apparatus which serves to transfer the sperm is remote from the generative opening, as in the male spiders, being placed on the ventral side of the enlai'ged second abdominal segment. Almost all insects are oviparous, and only a few, as the TacJdnw., Fig. 449.—Terminal region of the female genera
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectanimals, bookyear1892
