882 



MR. W. WOODLAND ON THE 



[Nov. 27, 



The Female Ueinogenital iSystem. 



The kidneys are, as shown in fig. 13 (PI. LX.), elongated 

 slender bodies commencing at a short distance from the anterior 

 extremity of the body-cavity (about four inches from the base of 

 the jDectoral fin) and extending posterioi'ly to the cloaca. They 

 come into apposition about three inches anterior to the cloaca. 

 Each kidney, for the greater part of its length, possesses its own 

 ureter, which lies on its ventral edge (text-fig. 137); where the 

 kidneys come into apposition, these two ureters fuse to form a 

 single duct which, without forming a urinary bladder, runs to the 

 extremity of the urinary papilla situated in the cloaca, where it 

 opens by a conspicuous aperture. The kidney-substance is 

 functional throughout its entire length, and there is therefore 

 not the slightest indication of a '• metanephros," .or separated-ofF, 

 posterior portion of the mesonephros, which alone remains 

 functional and possesses a separate duct, as occurs e. g. in the 

 Dogfish. Apparently very much the same condition obtains in 

 Scymnus lichia^'. As implied above, the kidneys are not sufficiently 

 developed to intrude upon the space occupied by the posterior 

 cardinal sinuses* : there is no "renal-portal system." 



Centropliortis calceus. 

 Diagrammatic transverse section in the region of the kidneys. 



D.A., dorsal aorta; K., kidnej' ; P., peritoneum ; P.C.S., posterior cardinal sinus ; 

 U., ureter; V., vertebral column. 



Two ovaries are present, as in C. squamulosus and C. granulosus 

 and many other Elasmobranchs. The oviducts open anteriorly, 

 just behind the pericardial cavity and anteriorly to the liver, 

 by a single large transversely- elongated aperture (PI. LXI. 

 fig. 18). Each oviduct, after thus bending in transversely to open 

 in the median line, proceeds posteriorly as a flattened duct (sup- 

 ported by a stout fold of the peritoneum) which, at the level of 

 the ovaries, expands into a small oviducal gland. This gland is 

 apparently functionless, since five embiyos (to be briefly described 

 below) were found lying quite free in the cavity of the main 

 uterine portion of the oviduct and without a vestige of an egg- 

 shell in connection with them. Posteriorly to the vestigial 

 oviducal gland, the oviducts each dilate into the thin-walled 

 uterus (smooth internally) which extends to within four or five 



* This statement refers to a theory respecting the origin and significance of the 

 "renal-portal system " contained in the succeeding paper. 



