250 E. A. BAUMGARTNER 



the hepatic duct. The pancreas in the adult Hes in the gastro- 

 duodenal loop. 



Eycleshymer and Wilson ('10) described the two ventral 

 anlages as dorso-lateral to the ductus choledochus. These 

 appear some time after the single dorsal anlage, arid union with 

 the dorsal pancreas does not take place until the embryo reaches 

 a length of about 29 mm. They found that the dorsal duct opens 

 into the duodenum just caudal to the stomach, and also mentioned 

 two ventral ducts. 



It is generally agreed by those who have described the duct 

 system in the adult urodeles that at least two ducts persist. 

 Hyrtl ('65) by means of injection in adult Cryptobranchus 

 found two pancreatic ducts, one of which joined the hepatic 

 duct. Oppel ('89) in Proteus has described an anterior and a 

 posterior set of ducts, the latter emptying into the ductus 

 choledochus. Kingsbury ('94) found one anterior duct opening 

 just behind the pylorus, and two caudal ducts which open 

 separately into the ductus choledochus. One pancreatic duct 

 has been described as persisting in adult Anura. Bates ('04) 

 stated that the pancreatic ducts join the hepatic ducts as they 

 pass through the pancreas. 



2. Early development of the pancreas and pancreatic ducts 



• As stated in the description of the liver, the pancreas develops 

 later than that organ. A well marked dorsal pancreas is to be 

 found in embryos 8 mm. long. A mass of cells in the dorsal 

 wall of the enteron is separated by a distinct transverse furrow 

 from the anlage of the stomach in front and from the yolk- 

 mass behind. Mitotic figures are to be found in this mass of 

 cells. 



In embryos about 9 mm. long there are three pancreatic 

 anlagen, two ventral and one dorsal, as has been described for 

 other amphibia. The two ventral anlagen appear as evagina- 

 tions posterior to the hepatic outpouching and caudal to the 

 ventral-lying gall-bladder. The evaginations of the pancreas on 

 the ventral wall of the gut extend in a longitudinal direction for 



