262 E. A. BAUMGARTNER 



in the forms studied by them. Greil ('05) reconstructed the 

 pancreatic anlagen as well as the branchial pouches of 7 and 7.5 

 mm. Bombinator embryos and showed the ventral pancreatic 

 evaginations as dorso-ventral to the attachment of the hepatic 

 outpouching and described them as lateral to the hepatic anlage. 



In Amblystoma the two ventral pancreases unite very early 

 along their medial sides. Braun ('06) has described the union 

 of the dorsal and the right ventral pancreas as occurring before 

 the union of the right and the left ventral anlagen and Greil 

 stated that the right ventral pancreas has united with the right 

 dorsal in 7.5 mm. embryos. The appearance of considerable 

 pancreatic tissue from the left side of the ventral anlage would 

 indicate that there is growth from this evagination. Goette 

 apparently thought this outpouching was rudimentaiy. The 

 presence of a left duct in some 12-13 mm. embryos indicates 

 that there is growth from the left side. Later stages show that 

 there is more growth on the right side. 



Although the lumen of the dorsal pancreatic anlage at first 

 extends anteriorly, the duct later extends upward and in the adult 

 again forward. Short lateral branches extend into the sur- 

 rounding pancreas. The ventral ducts fuse to form a single one 

 which divides into a right and left pancreatic duct. These again 

 divide into smaller rami, of which some from the right side extend 

 into the portion uniting with the dorsal pancreas. The dorsal 

 and ventral ducts, however, always remain separate. 



It is clear that in Amblystoma there is no complex pancreatic 

 duct system as Oppel ('90) has observed in Proteus. In possess- 

 ing a single dorsal duct Amblystoma resembles the Necturus as 

 described by Kingsbury ('94). The posterior set of ducts empty- 

 ing into the ductus choledochus as described by Oppel is quite 

 different from the single ventral duct in Amblystoma. Nor 

 does this conform to Kingsbury's description of two posterior 

 pancreatic ducts each of which open into hepatic ducts. I 

 cannot confirm Bates' ('04) observations concerning the several 

 pancreatic ducts which he stated opened into the hepatic ducts 

 within the pancreas. A table of the ducts as they have been 

 described in \'arious urodeles may be of interest. 



