DEVELOPMENT OF LIVER AND PANCREAS 



Joo 



shows it as a cap placed over the anterior end of the gut, dis- 

 tinctly separated from it by a groove and closely united to the 

 liver which lies in front of it. The right side shows only slight 

 indication of its later dorsal and caudal growth (fig. 30) . 



The dorsal pancreas forms an irregular elongated mass to the 

 right of the gastro-duodenal loop, but extends somewhat caudal 

 to it. To the right of the pancreas and ventrally lies the large 

 yolk-mass (fig. 30). The dorsal pancreas is now relatively and 

 actually nearer the ventral pancreas than in earlier stages. There 

 is as yet little evidence of any ventral growth of the anterior 



Fig. 30 Lateral view of a model of the pancreatic anlagen of an 11 mm. em- 

 bryo. X 40. D.pan., dorsal pancreas; G.b., gall-bladder; Li., liver; St., stomach; 

 V.pan., ventral pancreas; Y, yolk gut. 



Fig. 31 Lateral view of a model of the pancreas of a 13 mm. embryo. X 30. 

 D.pan., dorsal pancreas; G.B., gall-bladder; St., stomach; V.pan., ventral pan- 

 creas; Y, yolk-gut. 



end. The duct as in the younger stages lies mainly in the 

 cranial part of the mass forming the dorsal pancreas. It ex- 

 tends to the right and dorsalward and is nothing more than a 

 constricted part of the evagination. As seen in figure 29, it is 

 attached to the archenteron near the large yolk-gut. The 

 segment of the gut to which the dorsal pancreatic duct is at- 

 tached is the caudal end of the duodenal loop in Brachet's ('95) 

 'ascending limb' which posteriorly is completely constricted 

 from the ventral yolk-mass. Its attachment here, then as is 

 shown by later stages, is to the dorsal wall of the duodenum. 



