Fig. 9.
Diagram of the arrangement of the Urinogenital Organs in an adult
Male Elasmobranch.
m.d. rudiment of Müllerian duct; w.d. Wolffian duct, marked vd in front and serving as vas deferens; st. glandular tubuli; two of them are represented with openings into the body-cavity; d. ureter; t. testis; nt. central canal at the base of the testis; VE. vasa efferentia; lc. longitudinal canal of the Wolffian body.
In the male the following parts are present (woodcut 9):
(1) The Müllerian duct (md), consisting of a small rudiment attached to the liver representing the foremost end of the oviduct of the female.
(2) The Wolffian duct (w.d) which precisely corresponds to the Wolffian duct of the female, but, in addition to functioning as the duct of the Wolffian body, also acts as a vas deferens (vd). In the adult male its foremost part has a very tortuous course.
(3) The ureter (d), which has the same fundamental constitution as in the female.
(4) The segmental tubes (st). The posterior of these have the same arrangement in both sexes, but in the male modifications take place in connection with the anterior ones to fit them to act as transporters of the testicular products.
Connected with the anterior ones there are present (1) the vasa efferentia (VE), united on the one hand with (2) the central canal in the base of the testis (nt), and on the other with the longitudinal canal of the Wolffian body (l.c). From the latter are seen passing off the successive tubuli of the anterior segments of the Wolffian body in connection with which Malpighian bodies are typically present, though not represented in my diagram.