On the EoDaminaiion of the Human Pancreas. 153 
filled by the injection ; for in them the general and relative 
arrangement can be more distinctly seen than in those lobules 
which are completely distended, as in the latter case, owing 
to the amount of injection in them, a degree of opacity is pro- 
duced which renders the outline of many of the follicles some- 
what indistinct. Most of the sections which I have examined 
have been made with a Valentin's knife, and the preparations 
have been soaked for a short time in glycerine, which facili- 
tates the investigation of the pancreas, as of many other animal 
textures, by increasing the transparency. 
The large excretory duct of the pancreas extends along the 
centre of the gland from head to tail, and is enclosed on all 
sides by the large lobules. From it, at frequent intervals, 
smaller ducts proceed, which pass into these large lobules, 
and in them divide and subdivide into fine branches, for the 
ultimate lobules. Of these fine branches some arise at right 
angles, others at a more or less acute angle, and after a very 
short course they become connected with the ultimate gland 
follicles of the lobule to which they belong. Each duct, as a 
general rule, preserves the same calibre from the point at 
which it commences, to that at which it either gives off a 
branch, or terminates in an ultimate lobule. In some instances 
the ducts possess dilatations on their walls, which may either 
be confined to one side, or may exist at corresponding points 
on both sides. The same mode- of termination of the fine 
ducts in the ultimate lobules does not appear to exist in all 
cases, but admits of slight differences. In some instances the 
duct passes to the base of the lobule, and then from it, aa 
from a centre, the saccular dilatations of the ultimate follicles 
spring. In others the duct runs for a short distance along 
the base of the lobule, giving origin in its course to the fol- 
licles, which are connected to its sides and extremity. In 
either case the fine membrane forming the wall of the duct is 
continuous with the membrane constituting the wall of the 
follicles, so that the cavities of the follicles are continuous 
with that of the duct. The number of follicles present in an 
ultimate lobule varies considerably in different specimens. 
There are also great differences in their shape and size. 
Some are spheroidal, others laterally elongated, so as to pre- 
