. Elements of Comparative Anatomy. GENERATIVE ORGANS OF VERMES. 181 in its retracted state come to lie on its outer surface. Most Platy- laelminthesj except the Planarife, have the penis thus armed; it appears to be connected 1. with a more intimate copu- Fig. 86. Male apparatus, with parts of the female, of Bothryocephalus latus (after Lanclois and Sommer). a Testicular follicles: part only are represented, ve Their excretory ducts, vd Vas deferens, c Cirrus, cl Bag of cirrus. Other letters as in Fig. 87. § 149. There are greater varia- tions in the female appa- ratus. The ovaries ar
. Elements of Comparative Anatomy. GENERATIVE ORGANS OF VERMES. 181 in its retracted state come to lie on its outer surface. Most Platy- laelminthesj except the Planarife, have the penis thus armed; it appears to be connected 1. with a more intimate copu- Fig. 86. Male apparatus, with parts of the female, of Bothryocephalus latus (after Lanclois and Sommer). a Testicular follicles: part only are represented, ve Their excretory ducts, vd Vas deferens, c Cirrus, cl Bag of cirrus. Other letters as in Fig. 87. § 149. There are greater varia- tions in the female appa- ratus. The ovaries are, as a rule, one or two elongated tubes of no great size (Fig. 85, 0 ; 87, ov), in which the ovarian germs are formed. Where a single oviduct is present it becomes con- nected with accessory parts as it passes to the genera- tive pore, and varies in length. Several such may unite together and form a common oviduct. In most Rhabdocoela, as in the Ces- toda (Fig. 87, od) and Tre- matoda, the duct is single, though the ovaries are double. It is shortest in the Rhabdocoela, where, as in most of the Cestoda, it has an enlarged portion, which is clearly a receptaculum seminis. This organ appears as a unilateral diverticulum of the oviduct, and gradually becomes distinct. It is still more well-marked when it is attached to the base, or along the course of the oviduct (Fig. 85, r s), in the form of a stalked appendage. The Planarians have a double ovi- duct ; as a rule, a short portion only is common to both ducts, and functions as uterus or vagina. The oviducts are of some length in the land Planarians, the ovaries of which lie in the most anteinor parts of the body. They may be provided with short lateral branches along their course, which open into lacunar spaces of the coelom (Bipalium). This peculiar character raises the question as to whether these ciliated oviducts are parts of another system of organs; for there is no reason for supposing that ovarian tubes have degenerated s
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