DEVELOPMENT OF LIVER AND PANCREAS 245 



found in Ajnblystoma. The more marked divisions of the liver 

 into several lobes may partially explain this. The duct-system as 

 found in Necturus is quite different. Kingsbury here described 

 three hepatic ducts opening into the gut. These anastomosed 

 with each other and two were joined by the ventral pancreatic 

 ducts. The third is a duct direct from the gall-bladder which, 

 however, anastomoses with the other hepatic ducts. Gronberg 

 ('94) described three hepatic ducts which unite with the cystic 

 duct and form a ductus choledochus in Pipa americana. 



Bates ('04) has described the hepatic ducts in Amblystoma. 

 According to his description there are four heaptic ducts, two 

 of which join the bile-duct in its course through the pancreas 

 and the other two just as it opens into the intestine. It is possi- 

 ble that the two he found joining the bile-ducts are the right 

 medial and lateral rami, and the other two, the left medial and 

 lateral rami. In that case the ductus choledochus and the right 

 and left hepatic ducts were very short as was found in some of 

 the material used in this work. Or it may be that the two ducts 

 which joined the bile-duct as it opened into the intestine are the 

 two pancreatic ducts which have not fused until just at the 

 ostium of the hepatic duct. The first two ducts then would be 

 the right and the left hepatic ducts. I have never seen the 

 cystic duct (bile-duct as Bates terms it) open directly into the 

 common hepatic duct. 



From the models and drawings it will be seen that the gall- 

 bladder at first has a wide dorsal communication just caudal 

 to the hepatic lumen. As this communication constricts there 

 is formed a short large cystic duct extending dorsally into the 

 right hepatic duct. With further growth and division the cystic 

 duct extends more and more to the left until at the 15 mm. 

 stage it is almost horizontal and at the 20 mm. stage projecting 

 ventrally and somewhat anteriorly. Its earliest attachment is 

 to the ventral surface of the common bile-duct, but in the lateral - 

 ward shifting of the whole liver its attachment goes to the left 

 side of a right hepatic radicle. The connection of the cystic 

 duct to the gall-bladder in early stages is to its dorsal surface 

 about midwa}^ between cranial and caudal pole. Somewhat 



THE AMEKICAN JOURNAL OF ANATOMY, VOL. 19, NO. 2 



