DEVELOPMENT OF LIVER AND PANCREAS 



257 



denum near its caudal turn. The duct di\'ides shorth^ sending 

 out branches in all directions. 



The ventral ducts in a model of a 13 nnii. embryo come off 

 laterally from the hepatic ducts and immediately divide into 

 smaller rami. As a rule the ventral ducts at this stage fuse 

 into one tube ventral to the common duct. The ducts may join 

 the ventral wall of the common duct or the anterior end of the 

 gut, where the common bile-duct opens into the duodenum 

 (fig. 45). 



VPon 



Fig. 32 Drawing of a section showing the united acini of the dorsal and right 

 ventral pancreas. X 180. D.pan., from dorsal pancreas; V.pnn., from ventral 

 pancreas; Bl., blood vessel. 



Fig. 33 Lateral view of a model of the pancreas of a 15 mm. embryo. X 30. 

 D.pan., dorsal pancreas; D., duodenum; Li., liver; .S^, stomach; V.pan., ventral 

 pancreas. 



In a 15 mm. embryo as well as in later stages the dorsal pan- 

 creas forms the larger part of the whole organ. It joins the right 

 ventral pancreas by a neck of tissue, which is larger than in 

 the preceding stages (fig. 33). The ventral mass is crescentic 

 in transsection and lies just below the stomach, and anterior and 

 somewhat dorsal to the anterior end of the duodenum (fig. 45). 

 A part of the ventral pancreas extends anteriorly along the left 

 side of the gall-bladder. The pancreatic duct opens into the gut 

 ventrally and slightly to the left of the common bile-duct (figs. 



