254 E. A.'BAUMGARTNER 



are columnar in type but still contain considerable yolk. The 

 lumen extends a very short distance forward. 



In an 11 mm. embryo there has been considerable- further 

 development of the midgut region. The stomach has differ- 

 entiated to some extent. It has flattened dorso-ventrally, and 

 its posterior end is constricted and shifted to the left. The 

 duodenum extends ventrally to the left and has an anteriorly 

 directed portion which forms, with the stomach, the gastro- 

 duodenal loop. At its anterior end which Brachet ('95) has 

 termed the 'seconde courbure' in Axolotl the duodenum turns 

 to the right and is continuous with the caudal-extending yolk- 

 mass. Here at the cranial end is the ventral pancreas. The 

 pancreatic area appears at this stage as a narrow zone of the 

 gut marked off by furrows, anteriorly from the hepatic area and 

 posteriorly from the duodenum and yolk (fig. 30) . The pancre- 

 atic ducts are short and extend ventro-laterally from either side 

 of the common duct. These ducts are caudal to that part of 

 the common bile-duct which gives off towards the right ventral 

 side the cystic duct and anterior and somewhat dorsally two 

 lateral hepatic ducts. The groove separating the anterior end 

 of the pancreas from the hepatic tissue is well marked. The 

 gall-bladder extends downward and to the right of the midline 

 between pancreas and liver. A drawing of a section near the 

 anterior end of the duodenal loop shows what appears to be a 

 constricted forward projection of the gut (fig. 27). Somewhat 

 anteriorly the cells lining this constricted gut are of a tall col- 

 umnar type heavily laden with yolk as are the cells lining the 

 duodenum (fig. 28). This is the caudal end of the common duct. 

 Posterior to the section figured one can see the two lateral parts 

 of the pancreas distinctly separated from the constricted anterior 

 end of the gut where the common duct is attached (fig. 27). 

 About fifteen sections of lOju anterior to this are the ventro- 

 laterally projecting pancreatic ducts. The pancreas has grown 

 both anterior and posterior to the ducts, but the greater growth 

 has been forward (120/* caudalward and 140ju anterior). The 

 left pancreas grows anteriorly sending a small projection to the 

 left of the gall-bladder. A model of the pancreas of this stage 



