COURSE OF THE BILE. 201 



globules, which increase in number and size at c, , <?, c. They thus con- 

 tain both biliary material and oil globules, the quantity of the latter vary- 

 ST. ing with the nature of the food, and 



ffi\ sf^&i * n certani Diseased conditions occur- 

 '.?..\ ('.-i^K* rm g to so g rea t an extent as to give 

 rise to the aspect known as "fatty 

 .liver." This accumulation of fat is 

 connected with the respiratory func- 

 tion, not only in conditions of dis- 

 ease, but even in a state of health ; 



Hepatic cells magnified 400 diame'ters. f Qr? t ^ e more ener g e ti c the rCSpira- 



tion, the more free is the liver from fat. 



As the chyle passes through the mesenteric glands before it is dis- 

 charged into the circulation, so do the matters which have been taken up 

 by the vascular absorbents pass to the liver. In Chapter IV. the bile, 

 which is secreted from the portal blood, is treated of as taking part in the 

 function of digestion ; but there is another aspect under which we have 

 now to regard it. 



We speak of the circulation of the blood, because, setting out from the 

 heart, it conies back thereto, pursuing a course which returns H r othetical 

 upon itself. In the same metaphorical manner, according to spiral course of 

 the views of some, we might speak of the spiral motion of t 

 the bile ; for those of its constituents, which are first taken from the stom- 

 ach and small intestine by their veins, appear to pass in the portal circu- 

 lation to the liver. In that gland a preliminary partition of the constitu- 

 ents of the portal blood ensues, one stream setting off to the general cir- 

 culation through the hepatic veins, and another, the bile itself, returning 

 to the intestine. In the intestine another partition ensues ; the coloring 

 matter of the bile is dismissed with the faeces, and the residue, taken up 

 by the lacteals, passes through the mesenteric glands, and, either by the 

 thoracic duct or otherwise, gets into the blood circulation. It may there- 

 fore be perhaps thought that the constituents of the bile have been twice, 

 in close succession, in the digestive cavity, and have been twice absorb- 

 ed, first by the veins, and then by the lacteals ; and that, as it were, a 

 spiral course has been pursued. 



The question at once arises, what is the object of such a course ? Why 

 is there this return to the digestive cavity? The answer commonly given 

 is, the bile takes part in promoting the operation of digestion. But the 

 return may perhaps be, not for the purpose of inducing digestion, but for 

 the purpose of being acted on or digested itself. The separation of its 

 coloring matter, just alluded to, is a significant fact. 



The portal blood, as it is preparing to enter the liver, may be regarded 

 as systemic venous blood, the constitution of which has been altered 



