IN VARIOUS PHYSIOLOGICAL CONDITIONS. 2<59 



men, extractive matters, and salts, are moderately increased. The 

 fibrin during digestion remains the same as in the other vessels, 

 but after the completion of that process it can readily be torn and 

 forms only a loose diffluent clot. 



Compared with the blood of the jugular veins, portal blood is 

 poor in cells as well as in solid constituents generally ; these cells 

 are partly flocculent, are easily distorted, and soon become jagged 

 after their removal from the body. They are richer in hsematin 

 and poorer in globulin than the cells of the blood of the jugular 

 veins, but contain twice as much fat. The intercellular fluid 

 contains a fatty fibrin, which, however, is inferior in quantity to 

 that in the blood of the jugular veins. The serum contains on an 

 average less solid constituents generally (especially albumen), but 

 more fat, extractive matters, and salts. Biliary substances have not 

 been shown to exist in portal blood, and sugar only seldom occurs. 



The blood of the hepatic veins differs in constitution from that 

 of any other vessels. Compared with portal blood, it is poor in 

 water ; for if we assume the solid constituents of the two kinds of 

 blood to be equal, the amount of water in the portal blood will be 

 to that in the hepatic venous blood during digestion, when little 

 fluid has been taken, as 4 : 3, and after the completion of digestion 

 not unfrequently as 12 : 5. The clot of hepatic venous blood is 

 voluminous, and readily falls to pieces. While 100 parts of portal 

 blood yield 34 of serum, 100 parts of hepatic venous blood yield 

 only 15 of serum. Hepatic venous blood is far richer than portal 

 blood both in coloured and colourless cells, the latter presenting 

 every variety of size and form, and the former exhibiting heaps of a 

 distinct purplish red colour. Their cell-walls are less easily destroyed 

 than those of the blood of other vessels. While in the corresponding 

 portal blood there are 141 parts of moist blood-cells for every 100 

 parts of intercellular fluid, there are in hepatic venous blood 317 

 parts blood-cells for 100 parts of the intercellular fluid. The cells 

 of the latter blood are poorer in fat and salts ; especially poor in 

 haematin, or at least in iron, but somewhat richer in extractive 

 matters. These cells have a greater specific gravity than those of 

 portal blood (notwithstanding the diminished quantity of iron). 

 On comparing the specific gravity of both kinds of blood with that 

 of the serum, we find that the cells are lighter in relation to the 

 serum in the blood of the hepatic veins than in that of the portal 

 vein. The intercellular fluid of the former is far denser than 

 that of the latter ; it also contains a much larger quantity of solid 

 constituents ; but, on the other hand, it is either wholly deficient 



