386 
DR. LIONEL BEALE ON THE 
Of the Sacculi of the Ducts . — The so-called “glands” of the ducts liave been 
recognized by Kiernan and subsequent observers, but the attention of most anatomists 
has been directed to those which surround the large ducts, rather than to those which 
are found in the walls of ducts of smaller size. 
The so-called “ glands ” are small cavities of a rounded or oval form, or more or 
less branched, communicating with the cavity of the duct by a very constricted 
neck. A very simple sacculus is represented in Plate XIII. figs. 7 & 8, from a small 
duct of the pig’s liver. These glands are for the most part situated in the coats of 
the duct, and when injected scarcely project beyond its external surface. The larger 
branched glands, however, usually extend for some distance from the duct. The 
glands are usually situated all round the tube (pig, dog, monkey, cat, seal). In the 
smallest ducts in which they occur in the human subject, they are generally confined 
to two lines on opposite sides of the tube, but not unfrequently a few may be found 
between these lines of orifices. These orifices, which were described by Kiernan, and 
which lie tolerably close together, forming a straight row of openings on each side of 
the duct, are best seen when the small duct is laid open. They are, however, almost 
all of them the openings of small branches of ducts, many of which anastomose in the 
fibrous coat of the branch to which they belong, and probably very few only should 
be regarded as sacculi or glands, which are scarce in the small ducts of the human 
liver. The little dilatations connected with the ducts shown in Plate XIII. fig. 6 b, 
are examples of these so-called “glands” upon some of the smallest ducts in which 
they occur in the human liver. In the largest ducts in the human subject they are 
found all round the tube, but in unopened ducts many may escape notice in conse- 
quence of the pressure of the glass cover, by which the glands on the upper and 
lower surfaces are rendered almost invisible, while an undue prominence is given to 
those at the sides of the tube. 
The largest sacculi in the pig are branched, and are situated at the point where a 
smaller duct leaves the large trunk. 
In the human subject, at the point where the smaller ducts open into the large one, 
the lining membrane is so arranged as to form a valve which would tend to prevent 
the passage of the bile from the large into the small ducts, more especially as these 
latter run obliquely for some distance in the coats of the larger duct. 
In the pig, glands are numerous upon ducts from the to the y^th of an inch 
and more. They are situated all round the tube, and are rarely seen upon ducts 
below the of an inch in diameter. They are not present upon the small inter- 
lobular ducts, the walls of which are very thin. In the human subject, in the seal, 
and in the monkey, they are rare upon ducts below the of an inch in diameter. 
In the foetus they are common upon ducts xxofhs of an inch in diameter. They are 
rarely met with upon ducts in the cat’s liver less than-yfo^hs of an inch, and in those 
of the hedgehog below x^yths of an inch. 
Vasa aherrantia . — The most curious appendages to the ducts are the “vasa aher- 
