The only other developmental change of importance is the connection of the testes with the kidneys. This probably occurs in the same manner as in Selachians, viz. from the junction of the open ends of the segmental tubes with the follicles of the testes. In any case the vessels which carry off the semen constitute part of the kidney, and the efferent duct of the testis is also that of the kidney. The vasa efferentia from the testis either pass through one or two nearly isolated anterior portions of the kidney (Proteus, Triton) or else no such special portion of the kidney becomes separated from the rest, and the vasa efferentia enter the general body of the kidney. * * * * * In the male Amphibian, then, the urinogenital system consists of the following parts (Fig. 6): (1) Rudimentary Müllerian ducts, opening anteriorly into the body-cavity, which sometimes carry aborted _Kopfnieren_. (2) The partially or completely formed Wolffian ducts (ureters) which also serve as the ducts for the testes. (3) The kidneys, parts of which also serve as the vasa efferentia, and whose secretion, together with the testicular products, is carried off by the Wolffian ducts. (4) The united lower parts of Wolffian and Müllerian ducts which are really the lower unsplit part of the segmental ducts of the kidneys. [Illustration: FIG. 6. DIAGRAM OF THE URINOGENITAL ORGANS OF A MALE SALAMANDER. (_Copied from Leydig's Histologie des Menschen u. der Thiere._) _md._ Müller's duct (rudimentary); _y._ remnant of the secretory portion of the segmental duct Kopfniere; _Wd._ Wolffian duct; a less complete structure in the male than in the female; _st._ segmental tubes or kidney. The openings of these into the body-cavity are not inserted in the figure; _t._ testis. Its efferent ducts form part of the kidney.] In the female, there are (Fig. 7) (1) The Müllerian ducts which function as the oviducts. (2) The Wolffian ducts. (3) The kidneys. (4) The united Müllerian and Wolffian ducts as in the male. [Illustration: FIG. 7. DIAGRAM OF THE URINOGENITAL ORGANS OF A FEMALE SALAMANDER. (_Copied from Leydig's Histologie des Menschen u. der Thiere_.) _Md._ Müller's duct or oviduct; _Wd._ Wolffian duct or the duct of the kidneys; _st._ segmental tubes or kidney. The openings of these into the body-cavity are not inserted in the figure; _o._ ovary.] The urinogenital organs of the adult Amphibians agree in almost all essential particulars with those of Selachians. The ova are carried off in both by a specialized oviduct. The Wolffian duct, or ureter, is found both in Selachians and Amphibians, and the relations of the testis to it are the same in both, the vasa efferentia of the testes having in both the same anatomical peculiarities.