. Comparative anatomy of vertebrates. Anatomy, Comparative; Vertebrates. 472 COMPARATIVE ANATOMY nmnication with the body-cavity and cloaca. A vesicula seminalis may be present on the urinogenital duct (p. 457). Hermaphroditism occasionally occurs in the Annra; only one case (Triton taeniatus) is known amongst Urodeles. A body attached to the anterior end of the testis (" Bidder's organ") in various species of Toads contains cells quite similar to young ova, and a similar body is present at the anterior end of the ovary, the cells in which are, however, incapable of ripening. In the
. Comparative anatomy of vertebrates. Anatomy, Comparative; Vertebrates. 472 COMPARATIVE ANATOMY nmnication with the body-cavity and cloaca. A vesicula seminalis may be present on the urinogenital duct (p. 457). Hermaphroditism occasionally occurs in the Annra; only one case (Triton taeniatus) is known amongst Urodeles. A body attached to the anterior end of the testis (" Bidder's organ") in various species of Toads contains cells quite similar to young ova, and a similar body is present at the anterior end of the ovary, the cells in which are, however, incapable of ripening. In the males of Pelobates, Bufo, and Ran a temporaria, ova are at times developed within the substance of the testis (hermaphrodite, gland or ovotestis), and one testis may even be replaced by a rudimentary. Vr Fi<;. 355.—TESTIS AND ANTERIOR END OF KIDNEY OF Rana esculent a. (Semidiagrammatic.) Ho, testis ; L, longitudinal canal of the testicular network, from which the iiiter- renal network (C, C) arises ; .Y, kidney; q, q, transverse canals of the testi- cular network, which give rise to blind processes at f 15 Ur, urinogenital duct. ovary : in Rana, the Miillerian duct may then be as well developed as in the female. The ovaries of Urodela are always formed on a common plan: each consists of an elongated, closed tube, with a continuous lumen. In Anura, on the contrary, the ovarian sac (Fig. 356) is divided up into a longitudinal row of numerous (3 to 20) separate pockets or chambers, on the walls of which the ova are developed and project into the cavity, eventually breaking through into the coelome. The oviducts open far forwards into the body-cavity by funnel- shaped apertures ; they take a tolerably straight course along the outer borders of the kidneys to the cloaca in young animals, but become greatly convoluted and glandular later. A short distance. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability -
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