206 BILE BEHOVED FROM BLOOD BY FILTRATION. 



The liver does charges, and must correct, to a certain extent, the popular 

 not form bile, theory of its action. Does the liver really secrete bile ? Is 

 it the business of the so-called bile-secreting cells to withdraw the constit- 

 uents of that liquid from the blood, and combine them together into this 

 viscid yellow liquid ? I think not ; for it is a matter of demonstration that 

 not only every constituent of the bile, but the bile itself, pre-exists in the 

 blood, and it is just as unphilosophical to burden those cells with the 

 duty of forming it as it would be to believe that a like agency is needful 

 for the appearance of urea in the kidney. Moreover, we must constantly 

 bear in mind the extreme instability of this substance, how readily the 

 yellow bile, of carnivorous animals becomes green by partial oxidation, 

 and the green bile of the herbivora yellow by deoxidation. It spontane- 

 ously changes in its downward career, and any differences in quality or 

 character which we might impute to the action of the cells upon it may 

 be equally well attributed to its own inherent principle of change. 



For these reasons, I believe that the bile simply transudes from the 

 Manner of blood, and that the cells of the lobules have no special relation 

 removing it. to j t beyond this, that it oozes past their interstices, or, perhaps, 

 by *physical imbibition, finds access to their interior. I see no reason 

 that these cells should form it when it pre-exists in the blood, nor does 

 the state of the affluent and effluent blood offer any contradiction to this 

 conclusion. In all discussions of the functions of this organ founded 

 upon a comparison of the portal and hepatic venous blood, the relative 

 quantity of water which they contain, and its great and even rapid fluc- 

 tuations, should always be borne in mind. As might be expected, portal 

 blood contains far more water, and, even after abundant drinking, the 

 amount in the hepatic venous blood has by no means increased to the 

 extent that might have been expected. It is for these reasons that the 

 bile varies so greatly at different periods in its specific gravity and 

 fluidity. 



The blood of the portal vein is, moreover, periodically varying in its 

 Variation in constitution, according to the state of activity of the organs 



tfoVorfoeJor- from wllich i1: is tefog derived - In tlie first sta g es of diges- 

 tai blood. tion the stomach is supplying it in unusual quantities, and 

 with the ingredients which its veins have been absorbing from the result 

 of histogenetic digestion. A little later, the same thing occurs with the 

 intestine. At another period the supply from the spleen varies. 



The explanation which Mr. Handfield Jones has recently given of the 

 Function of the function of the hepatic cells that they manufacture liver- 

 hepatic cells, sugar deserves attentive consideration, more particularly if 

 we likewise impute to them the production of liver-fat ; for this would at- 

 tach them rather to the ramifications of the hepatic veins as a part of their 

 instrumental mechanism, and assign them only a very indirect relation to 



