GLYCOGENIC FUNCTION OF THE LIVER. 369 



goes on in it, which is nearly related to or associated with nutri- 

 tion. 



The swelling of the lymphatic glands after extirpation of the 

 spleen confirms its relation to these organs, and the fact is undis- 

 puted that it is a source of the white corpuscles of the blood ; 

 but the paucity of evidence after this operation as to changes in 

 the number or character of the red disks proves that if the spleen 

 be either the place of origin or destruction of the red corpuscles 

 it cannot be the only organ in which they are produced or de- 

 stroyed. 



GLYCOGENIC FUNCTION OF THE LIVER. 



Of all the organs that modify the composition of the blood as 

 it flows through them, the liver plays the most important part in 

 elaborating the circulating fluid. The elimination of the various 

 constituents of the bile, which has already been mentioned as 

 necessary for the purification of the blood, and useful in aiding 

 absorption, is probably but a secondary function of this great 

 gland. The production of a special material animal starch 

 essential to the nutrition and growth of the texture is, in all 

 probability, the main duty of the liver cells, and possibly the 

 constituents of the bile are but the by-products which must be 

 got rid of, resulting from the chemical processes of the manu- 

 facture. 



In the chapter on the digestive secretions the structure of the 

 liver was mentioned, and attention was directed to the peculiari- 

 ties of its double blood supply. A relatively small arterial twig 

 takes blood to it from the aorta, while the great portal veins dis- 

 tribute to it all that large supply of blood which flows through 

 the intestinal tract and the spleen. 



The blood in the vena porta during digestion can hardly be 

 called venous blood, for much more passes through the intestinal 

 capillaries when digestion is going on than is necessary for the 

 nutrition of the tissue of the intestinal wall. The portal blood 

 is further to be distinguished from ordinary venous blood from 

 the fact that it has just been enriched with a quantity of the sol- 



31 



