215 
2) That most of the longitudinal muscle bundles of the cystic 
duct continue down the duct without entering the valve, but still there 
are some of these bundles, which (having reached the level of the 
valve) bend around at almost right angle and run out into the fold. 
3) We have no evidence that the diagonal fibres take any part 
in the musculature of the valves of HEISTER. 
We believe, therefore, that the transverse muscle bundles pre- 
dominate in the valves of HEISTER. Those valves nearest the common bile- 
duct are quite small and either contain very little muscle or none at all. 
Conclusions. 
The principal results of the research may be briefly summed up 
in tabular form; under the various heads only the most general find- 
ings are mentioned. 
Dog | Rabbit | Man 
Distribution of the 
muscle bundles 
Distribution of the | Distribution of the 
muscle bundles muscle bundles 
Transverse ') Transverse Transverse 
a) Gall-bladder Longitudinal onen anal Den 
Diagonal lagona iagona 
Transverse Transverse Transverse 
b) Cystic duct Longitudinal Longitudinal Longitudinal 
Diagonal Diagonal Diagonal 
( The transverse fibres of the 
cystic duct run around in the 
valves of HEISTER in a cir- 
Val f cular direction. The longi- 
en tudinal fibres bend at right 
angle and run out into the 
| valve. Diagonal fibres appa- 
| al do not enter the val- 
ves of HEISTER. 
f _ | Transverse Transverse 
c) Hepatic duct Longitudinal Longitudinal Longitudinal 
| _ Diagonal Diagonal 
F Transverse Transverse Transverse 
d) nen bile- Longitudinal Longitudinal Longitudinal 
Diagonal = Diagonal 
Pl Suni Each duct preserved | Each duct preserved | Each duct preserved 
e) nn Ar its typical struc-| its typical struc- | its typical struc- 
i e ys nd ture; the wall of; ture; the wall of| ture; the wall of 
6 peo bil each gradually| each gradually| each gradually 
re an merging into that | merging into that; merging into that 
wee of the others. of the others. of the others. 
f) Duodenal por- 
tion of aie A sphincter muscle} A sphincter muscle | A sphincter muscle 
Common bile- exists. exists. exists. 
duct 
1) These terms 
are used with reference to the long axis of the duct. 
