DEVELOPMENT OF LIVER AND PANCREAS 261 



dahvard. As the duodenuin shifts downward and to the left 

 with relation to the stomach, this portion of the pancreas Hes 

 more and more to the right of the chiodenum and for a consider- 

 able distance it lies ventral to the stomach. The pancreas 

 extends caudalward almost to the gastro-duodenal loop. 



A short distance from the caudal end of the pancreas the dor- 

 sal pancreatic duct is connected to the right side of the duo- 

 denum (fig. 35). This duct extends forward almost to the point 

 where the dorsal pancreas divides into several parts and gives 

 off small branches as it comes to lie more and more in the dorsal 

 part of the gland. The duct of the ventral pancreas joins the 

 common bile-duct (fig. 35) where it opens into the left side of 

 the duodenum or beside it. The pancreatic duct is ventral to 

 the common bile-duct and almost immediately divides into right 

 and left ducts. The left duct is the more ventral and soon 

 divides into branches which turn \'entral and caudally (fig. 35). 

 The right duct extends anteriorly and upward and sends some 

 branches into that part of the dorsal pancreas which joins the 

 \'entral. 



4. Discussion 



As has been found in other amphibia, the pancreas in Ambly- 

 stoma is developed from three anlagen, two ventral and one 

 median dorsal. As in other forms the dorsal develops earlier 

 and, as Stohr and others have stated, from only one evagination. 

 This is found just caudal to the anlage of the stomach. In none 

 of the embryos studied is there evidence of an outpouching 

 toward the left as Goeppert ('91) described in another form. 

 Greil ('05), however, in j^oung Bombinator embryos recon- 

 structed right and left dorsal pancreatic outpouchings. Older 

 embryos show that there has been considerable growth of the 

 dorsal pancreas in a cranio-caudal direction with the lengthen- 

 ing of the duodenum, and a division of the anterior end into 

 several processes, one of which joins the ventral pancreas. 



In the very earliest stages the ventral anlagen are caudal 

 to the gall-bladder. Goeppert ('91) and Ghronshitzky ('00) 

 have described these anlagen as lateral to the cystic evagination 



THE A^rEnICAN joukx.nl of axatomv, vol.. 19, xo. 2 



