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becoming continuous with fibres of the inner circular muscular coat 
of the intestine. 
b) By running forward, turning away from the bile-duct and blend- 
ing with fibres of the inner circular muscular coat of the intestine. 
c) By running forward, passing under the annulus of muscle about 
the mouth of the common bile-duct and becoming lost among these 
fibres. 
d) One side ends according to b); the other side according to c). 
The mode of termination in Fig. 2 corresponds to that described 
under c). At the point O, some fibres of the inner circular muscular 
coat bend around the common bile-duct forming a U-shaped curve. 
This is the place of entrance of the common bile-duct into the muscle 
of the inner circular muscular coat of the intestine. 
The common bile-duct is finally teased completely away and the 
muscle fibres of the inner circular muscle coat are revealed. These 
muscle fibres are found to be present from the point A to the point M, 
Fig. 1. It will be remembered that fibres of the inner circular mus- 
cular coat pass over the common bile-duct from the point A to the 
point R. Removal of the remaining fibres of the inner circular mus- 
cular coat discovers the outer longi- 
tudinal muscle coat of the intestine. In 
Fig. 3, the point F represents the ar- 
rangement of the fibres of the outer 
longitudinal muscle coat of the intestine 
at the place of entrance of the common 
bile-duct into the intestinal wall. 
Fig. 3. Macerated duodenal portion of the common bile-duct of dog. The relation 
of the common bile-duct to the longitudinal muscular coat of the intestine is shown. xX 4. 
In addition to this general description the following points deserve 
to be mentioned. In some specimens at the pancreatic side of the 
mouth of the common bile-duct additional muscle bundles more or less 
involved with some already described can be made out. The resulting 
structure suggests a point d’appui. One never sees such a point 
d’appui developed on the non-pancreatic side. 
In all cases the course of the common bile-duct through the wall 
of the duodenum is slightly oblique with reference to the inner cir- 
cular muscle coat of the intestine; in most cases the course is also 
slightly curved — the convex side being the pancreatic side of the 
common bile-duct. 
The Duct of Wirsung. — Speaking relatively, the duct of 
