SECRETORY APPARATUS OF THE LIVER. 
475 
there exist no lobules there with which they can be in relation ; the arrangement, 
however, appears to be quite in harmony with the description I have given. Those 
lobules which adjoin the portal canal on the side of the branch of the hepatic duct 
contained in it, have a collateral canal running along their sides from which interlo- 
bular ducts pass in at each corresponding fissure ; the floor and sides of this canal 
are beset on their outer surface with epithelial cells ; the remaining lobules, by far 
the greater number, which adjoin the branch of the portal vein, have a similar col- 
lateral canal from which interlobular ducts proceed, but it differs from the preceding 
one in not having a layer of cells on its outer surface ; from both these canals 
branches pass ofF, which probably directly proceed to enter the main duct*. 
The most important point in the foregoing description relates to the absence of 
real tubular ducts from the interior of the lobules, a view which, proposed some time 
ago by Mr. Bowman, has lately been contradicted by the German anatomists before 
mentioned, who in this respect coincide with Mr. Kiernan ; I will therefore shortly 
state the proofs which appear to me satisfactory on this point. These are, first, the 
non-existence of basement membrane in the interior of the lobules, which in com- 
mon with Mr. Bowman I have been unable to detect; yet were this simplest consti- 
tuent of a duct present it could hardly escape notice, especially as in other glands it 
admits of being readily demonstrated ; at the broken margin of a lobule it may be 
well seen that the projecting extremities of the linear series are quite free, and ex- 
hibit no trace of any containing membrane. Secondly, if the margin of a lobule be 
carefully examined, where it forms the side of a fissure, the basement membrane may 
often be clearly seen, and through its transparent texture the terminal cells of the 
linear series are easily distinguished, resting against and contained by it. Now were 
the membrane inflected to form lobular ducts, surely some indentation or irregularity 
would be visible at the margin of the lobule, but I have often traced the outline 
carefully without observing any such. A third proof is supplied by the result of 
some experiments which I made on rabbits. I tied the duct. com. choled., and 
shortly after death, which took place at periods varying from one to four days, I ex- 
amined their livers : these organs were found to be beset on the surface and through- 
out their substance with numerous spots of deep yellow colour, evidently produced 
by accumulation of bile ; a section of these spots, examined under the microscope, 
showed that they were very partial, never extending throughout the whole of a 
lobule, but frequently situated in two or more adjacent ; their outline was always 
well-defined, and not the slightest appearance of a distended plexus of ducts could 
be observed : this last evidence appears to me conclusive. I can hardly conceive that 
if any plexus of anastomosing ducts existed, the accumulation of bile should take 
place in definite spots, and those not always situated in a single lobule, but in two or 
three adjacent. With regard to the proofs from injection which may be adduced in 
* The description above given has been taken from examination of the larger portal canals ; with regard to 
the smaller ones I cannot speak so decidedly, but it seems fair to infer that the arrangement is similar. 
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