312 



COMPAKATIYE AXATOM Y . 



FIG. 244. MALE UIUNOGENITAL APPARATUS OF THE STV i:<.::nv 



N, N l , N z , the different portions of the kidneys ; ,SV/, ,V/', XG' 2 , tlie different parts 



of the ducts of the kidneys ; -Vd, J r d l > I'd 2 , vas deferens ; -Ho, testis : 



Ve, Ve, network of the vasa efferentia ; MG, Mullovian duct, which nnjte.s .with 



the collecting duct of the kidneys at MG 1 ; t, point at which the two collecting 



- ducts of the kidneys iinite." 



development. 1 Posteriorly, the oviducts open into the cloaca 

 somewhat behind the apertures of the ureters either separately, 

 or by a common canal. 



1 The greater number of Sharks are viviparous. (Concerning the umbilical 

 placenta found in Mu.stelus laevis and Carcharias, comp. p. 12.) 



The embryos of Mustolus antarcticus are provided with membranes which bear 



