199 
the color and brilliancy of raw silk and, having absorbed water, stand 
out quite beautifully. 
To demonstrate the muscle of the gall-bladder, cystic duct, hepatic 
duct and common bile-duct, the gall-bladder and hepatic duct were 
dissected from the liver; the hepatic duct was ligated and after ejecting 
the bile through the common bile-duct by pressure on the gall-bladder, 
the macerating mixture was injected up the .common bile-duct until 
the walls of the gall-bladder were distended. The common bile-duct 
was then ligated and the whole mass placed in a vessel containing the 
same macerating mixture. The rest of the process in the same as for the 
duodenal specimen. The period of maceration in nitric acid, glycerine 
and water has to be varied according to the delicacy of the specimen. 
b) The second method employed was that of fixing, embedding, 
sectioning and staining the various parts. The specimens were fixed 
in absolute alcohol, formalin, or corrosive sublimate and imbedded in 
celloidin or paraffin. The principal stain used was that suggested by 
Van GiEson, since the differentiation of minute quantities of smooth 
muscle from the surrounding connective tissue by this stain is quite 
exquisite. Other methods of staining were, however, employed for 
purposes of comparison. 
The Sphincter of the Common Bill-duct in the Dog. 
That portion of the duodenum which contains the duodenal papilla 
having been macerated in a mixture of nitric acid, glycerine and water 
as described above, was examined in the 
following manner. The intestine was cut 
along its longitudinal axis on the side oppo- 
site the duodenal papilla and laid open. The 
Fig. 1. Macerated duodenal portion of the common 
bile-duct of dog. The mucous membrane, muscularis 
mucosae and submucosa of the intestine have been re- 
moved. 4. The description of all of the letters used 
is given at the end of the article. En 
Index of all the Letters used in the Figures. 
B Common bile-duet; CZ Circular muscular coat of the intestine; CS Fibres of the 
circular muscular coat of the intestine which have a distribution indicative of a secon- 
dary sphincter; @B Next to gall-blatter; ZR Independent rings of muscle embracing the 
common bile-duct; A Fibres which arise on the common bile-duct and run around the 
duct of WIRSUNG to become continuous with similar fibres of the opposite side; LJ Longi- 
tudinal muscular coat of the intestine; L# Fibres of the longitudinal muscular coat of 
the intestine which turn and run forward toward the ampulla of Vater; M Mouth of the 
common bile-duct; MI Mucous membrane of the intestine; N Muscle bundles which have 
origin in the median line of the common bile-duct and afterwards run forward parallel 
with the long axis of the duct; NZ Next to common bile-duct; S Sphincter fibres; SZ Sub- 
mucosa of the intestine; W Duct of Wirsuna; X Those fibres of the sphincter which 
become detached laterally and run down the intestine, 
