Fig. 1. Diagrammatic representation of excretory organs on one side of a
male Scyllium canicula, natural size.
Fig. 2. Diagrammatic representation of the kidney proper on one side of a
female Scyllium canicula, natural size, shewing the ducts of the kidney and
the dilated portion of the Wolffian duct.
Fig. 3. Opening of the ureters into the Wolffian duct of a female Scyllium
canicula. The figure represents the Wolffian ducts (_wd_) with ventral
portion removed so as to expose their inner surface, and shews the junction
of the two W. ducts to form the common urinal cloaca, the single external
opening of this (_o_), and openings of ureters into one Wolffian duct
(_ou_).
Fig. 4. Anterior extremity of Wolffian body of a young male Scyllium
canicula shewing the vasa efferentia and their connection with the kidneys
and the testis. The vasa efferentia and longitudinal canal are coloured to
render them distinct. They are intended to be continuous with the
uncoloured coils of the Wolffian body, though this connection has not been
very successfully rendered by the artist.
Fig. 5. Part of the Wolffian body of a nearly ripe male embryo of Scyllium
canicula as a transparent object. Zeiss a a, ocul. 3. The figure shews two
segmental tubes opening into the body-cavity and connected with a primary
Malpighian body, and also, by a fibrous connection, with a secondary
Malpighian body of the preceding segment. It also shews one segmental tube
(_rst_) imperfectly connected with the accessory Malpighian body of the
preceding segment of the kidney. The coils of the kidney are represented
somewhat diagrammatically.
Fig. 6. Vasa efferentia of a male embryo of Scyllium canicula eight
centimetres in length. Zeiss a a, ocul. 2.
There are seen to be at the least six and possibly seven distinct vasa
going to as many segments of the Wolffian body and connected with a
longitudinal canal in the base of the testis. They were probably also
connected with a longitudinal canal in the Wolffian body, but this could
not be clearly made out.
Fig. 7. The anterior four vasa efferentia of a nearly ripe embryo.
Connected with the foremost one is seen a body which looks like the remnant
of a segmental tube and its opening (_rst?_).
Fig. 8. Testis and anterior part of Wolffian body of an embryo of Squatina
vulgaris.
The figure is intended to illustrate the arrangement of the vasa
efferentia. There are five of these connected with a longitudinal canal in
the base of the testis, and with another longitudinal canal in the Wolffian
body. From the second longitudinal canal there pass off four ducts to as
many Malpighian bodies. Through the Malpighian bodies these ducts are
continuous with the several coils of the Wolffian body, and so eventually
with the Wolffian duct. Close to the hindermost vas efferens is seen a body
which resembles a rudimentary segmental tube (_rst?_).