198 
agree as to the distribution of the smooth muscle fibres which are 
found in the gall-bladder; but, concerning the presence and the exact 
course of the muscle of the remainder of the biliary system there has 
been a marked diversity of opinion. DuverNey (and also HENLE) 
states that the muscle fibres of the gall-bladder near its neck show 
a circular disposition which might be regarded as a sphincter. TOBIEN, 
however, found a ring of muscle fibres in the cystic duct near the gall- 
bladder, which he called a sphincter. Other observers have not ap- 
parently been able to find such a sphincter of either the gall-bladder 
or the cystic duct. 
The presence of a sphincter muscle about the duodenal extremity 
of the common bile-duct, was suspected as early as 1681, for in that 
year GLisson thought he had demonstrated its presence by observing 
that the orifice of the common bile-duct would close after removal of 
a probe. 
With the exception of von LuscuKa’s work in 1869 which really 
does not describe a sphincter muscle, no attempt was made to reveal 
the anatomy of this part until the subject was approached by Oppt. 
In 1887, Oppı undertook to demonstrate the sphincter of the common 
bile-duct and after a careful study of the subject brought forth the 
results which have been briefly refered to in the introduction to this 
article. 
Methods Employed. 
In the present investigation two methods were employed to de- 
monstrate the smooth muscle of the biliary passages. 
a) The more important of these, in some respects, is the method 
used by Marcaccr for demonstrating the musculature of the papilla 
mammae. The method consists in macerating the tissue to be examined 
in a mixture of equal parts by volume of concentrated nitric acid, 
glycerine and water. In applying it to the present study, the vertical 
portion of the duodenum was cut out and ligated at its two extremities. 
A cannula was introduced into the ductus choledochus and the above- 
mentioned mixture was injected into the intestine until its walls were 
well distended. The common bile-duct was next ligated and the entire 
specimen placed in a vessel full of the same macerating mixture. 
After a certain period of time the tissue was removed and placed in 
water. The intestine having been cut open on the side opposite the 
mouth of the common bile-duct, the mucous membrane was re- 
moved quite easily with forceps. The water was changed and the 
specimen allowed to remain thus for 24 hours. At the end of this 
time the specimen is ready for examination. The musele fibres have 
