DEVELOPMENT OF THE ELASMOBRANCH LI\T]R 



357 



The gall bladder is an elongated tubular sac which lies along 

 the right margin of the cystic lobe. It is imbedded in hepatic 

 parenchyma except for a little of the right surface which receives 

 a peritoneal investment. The cystic duct arises from the anterior 

 end of the gall bladder and proceeds directly dorsally. It then 



nhtp.i. 



R.l.m 



i/sub.nt. 



Fig. 14 A dissection of an Acanthias embryo 20 cm. in-length. X f . The 

 ventral abdominal wall has been cut away and the vitelline duct severed at its 

 connection with the internal yolk stalk. The gall bladder ahd main hepatic ducts 

 have been dissected out. The large veins of the liver have been omitted from this 

 drawing. C.L, cystic lobe; D.chol., ductus choledochus; D.cyst., cystic duct; 

 D.hep.L, left hepatic duct; D.vit., vitelline duct; G.bl., gall bladder; I.y.s., internal 

 yolk sac; L.I., lateral lobe; Pane, pancreas; V.int., valvular intestine; V. subint,, 

 subintestinal vein. 



Fig. 1.5 Diagrammatic representation of the gall bladder and liver ducts of 

 Acanthias as seen from above. D.chol., ductus choledochus; D.cyst., cystic duct; 

 D.hep.L, left hepatic duct; D.hep.r., right hepatic duct; G.bl., gall bladder; R.a.L. 

 anterior left hepatic ramus; R.a.r., anterior right hepatic ramus; R.l.m.. left 

 medial hepatic ramus; i?. p. L, posterior left hepatic ramus; R.p.r., posterior right 

 hepatic ramus; R.r.m., right medial hepatic ramus. 



makes a sharp semicircular curve and proceeds posteriorly to 

 join the ductus choledochus. In older embryos and adults there 

 is no line of demarcation between the cystic and common bile 

 ducts. The ductus choledochus extends backward ventral to the 



