360 THE ADRENAL, GENERAL MOTOR, AND VAGAL SYSTEMS. 



its plasma contains and the mode of distribution of its terminal 

 capillaries, supplies the exogenous chemical energy which initiates 

 and sustains all reactions in the hepatic lobule that require oxygen. 



2. The nervous supply of the liver is composed, first, of ter- 

 minal subdivisions of the general motor system (splanchnic-sym- 

 pathetic), which furnish nervous energy during the passive sta/je 

 of functional activity by insuring tonic contraction of all vessels, 

 and, second, of terminal subdivisions of the vagus, which excite and 

 govern the active stage of functional activity by regulating the cali- 

 ber of the hepatic arterioles and by supplying nervous energy to the 

 hepatic cells. 



8. In the normal subject the liver is anatomically isolated 

 from structures that come into contact with bacteria, and protected 

 against their intrusion by the bactericidal products of the intestinal 

 glands and follicles. 



4. The capillaries of the hepatic lobules, owing to the ad- 

 mixture therein of the hepatic artery's oxidizing substance with the 

 portal vein's waste-laden blood, are the seat of several functions 

 now ascribed to the hepatic cell. 



5. Blood-pigments and iron, derived from the intestine and 

 spleen, simultaneously penetrate the hepatic lobule, and combine 

 with the oxidizing substance therein to form hcemoglobin. The un- 

 combined pigment is eliminated with the bile as bilirubin. 



6. Urea is the end-product of three successive reactions, viz.: 

 (1) nitrogenous bodies are reduced to amides in the afferent veins, 

 mesenteric and portal; (2) the amides are dissociated into 

 ammonia, carbonic acid, and water by the oxidizing substance in 

 the hepatic lobule; (3) urea is formed by synthesis in the efferent 

 veins, hepatic and vena cava. 



7. The hepatic cell contains, besides its vacuoles and nuclei, 

 numerous canaliculi (S chafer) and a vesicular vacuole which 

 opens into the bile-capillaries by a canaliculus (Kupffer); the 

 canaliculi and the vesicular vacuole are probably connected. 



8. Glycocholic acid and taurocholic acid are functional acids, 

 inasmuch as they dissociate and appropriate waste-products, and, 

 under the influence of the oxidizing substance, convert them into 

 excrementitious products in the canaliculi of the hepatic cells. 



9. The waste-products so converted by the biliary acids and 

 the latter themselves, constituting bile, are transferred, along with 



