203 
Wiırsung was found in many cases to run among the muscle fibres of 
the point d’appui situated at the pancreatic side of the mouth of 
the common bile-duct. The duct of WırsunG joins the common bile- 
duct at its extreme end; the pancreatic and common bile-duct opening 
side by side. The annulus of muscle fibres about the mouth of the 
common bile-duct accordingly also embraces the mouth of the duct of 
WIRSUNG. 
In Fig. 3 point W, the arrangement of the outer longitudinal 
muscle coat of the intestine at the point of entrance of the duct of 
WirsuNG into the intestinal wall is illustrated. 
A study of serial cross-sections of the duodenal 
portion of the dog’s common bile-duct. — Two sets of serial 
sections were prepared and examined. The specimens were stained in 
bulk with borax carmine and embedded in paraffin. The following 
drawings are taken from sections at different points in the course of 
the common bile-duct through the intestinal wall. They begin near 
the duodenal papilla and pass back towards the point of entrance of 
the duct into the intestinal wall (Figs. 4 to 8). 
nl, 
Dosnd HO, 
Ww ae a x i 2 
ely 
Fig. 4. Cross-section near the orifice of the duodenal portion of the common bile- 
duct of dog. X 30. 
Fig. 4 is made from a cross-section taken through the duct 
of Wırsung and the common bile-duct near their junction. Most inter- 
est attaches to the appearances in the submucosa. Here are to be 
