The development of the choledochus and pancreatic ducts in the gecko, Gymnodactylus kotschyi

Abstract

The development of the choledochus duct and pancreatic ducts in thirty-five embryos of the gecko, Gymnodactylus kotschyi, ranging from stages 20 to 34 (time of hatching), can be divided into four phases: First Phase: Four ducts enter the gut by separate portals. The first duct, posterior to the stomach, is from the ventral anlage of the ventral pancreas. The second is from the left anlage of the ventral pancreas. The third is the choledochus duct. The fourth duct to enter the gut posterior to the stomach is that of the dorsal pancreas. Second Phase: Three ducts enter the gut separately. The duct from the ventral anlage of the ventral pancreas persists, while the duct from the left anlage of the ventral pancreas disappears. The choledochus and dorsal pancreatic ducts enter the gut separately. Third Phase: Two ducts enter the gut separately. The choledochus and dorsal pancreatic ducts unite to enter the gut as a common duct. The ventral pancreatic duct enters the gut separately. Fourth Phase: One common duct results from the fusion of the ventral pancreatic duct with the common duct already formed from the dorsal pancreas and the choledochus duct. The material was collected from the Bosphorus region and killed inZenker's orBouin's B-3, and sectioned and stained in eitherDelafield's haematoxylin and eosin or borax-carmine and lichtgrun.