GLANDS. 411 



confirmatory testimony of very many high microscopical au- 

 thorities. 



The first observer who, I believe, expressed doubts of the 

 existence of a lobular biliary plexus was Mr. Bowman, to 

 whose numerous microscopical researches, science is so much 

 indebted. 



More recently still Dr. Hanfield Jones, in a paper " On the 

 secretory Apparatus of the Liver * " has not merely expressed 

 the same doubts, but has entered fully into the reasons on 

 which his opinion is based. 



Dr. Jones founds his belief of the non-existence of a lobular 

 biliary plexus upon the following observations : 



" First, the non-existence of basement membrane in the interior of the 

 lobules which, in common with Mr. Bowman," he writes, " I have been 

 unable to detect ; yet were this simplest constituent 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 broken extremities of the linear series are quite free, and exhibit 

 no trace of any containing membrane. Secondly, if the margin of a 

 lobule be carefully examined, where it forms the sides of a fissure, the 

 basement membrane may often be clearly seen, and through its transpa- 

 rent 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 two to four days, I examined their livers : these organs were 

 found to be beset on the surface and throughout their substance with 

 numerous spots of deep yellow colour, evidently produced by accumu- 

 lation 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." 



Philosophical Transactions, 1846. 



