THE LIVER. 59 



ries; they are best seen on tearing the organ, are united in mass 

 by the elongations of the cellular coat, and traversed by the 

 trunks of the blood vessels. Each of these granulations is 

 about the size of a millet seed, and is a representative ofjlhe 

 entire gland, as its structure is complete in itself; being formed 

 by the terminations of the blood vessels, and by the origin of a 

 branch of the hepatic duct, called the porus biliarius. When 

 examined with a microscope, it is said that these acini are ob- 

 served to be composed of a yellow and of a brown-looking sub- 

 stance; it has not, however, occurred to me to see the distinc- 

 tion in a very satisfactory way, though it is recognised by an- 

 atomists of high authority.* 



The Liver is made extremely vascular by the ramifications 

 of three kinds of blood vessels, the Vena Portarum, the Hepatic 

 Artery, and the Hepatic Veins. The two first convey the 

 blood to it, and the third removes it again, into the general cir- 

 culation, by emptying into the ascending vena cava. There 

 are also the commencing radicles of the hepatic duct, lympha- 

 tic vessels, and the nerves. 



The Vena Portarum having arisen from the junction of all 

 the veins of the stomach, intestines, pancreas and spleen, is 

 about three inches in length when it reaches the transverse fis- 

 sure, by going over the duodenum and under the pancreas. It 

 immediately divides into two branches, called collectively the 

 Sinus VenaB Portarum, which is at right angles with the trunk 

 of the vein; the right branch being the shortest and largest, is 

 distributed by radiating trunks to the right lobe of the liver; 

 the left branch is distributed, after the same manner, to the left 

 lobe, to the lobulus spigelii, and to the lobulus quartus. Some 

 of its branches anastomose with the hepatic veins, which ac- 

 counts for the ease with which an injection will pass from one 

 to the other. Other branches of a smaller description anasto- 

 mose with the biliary ducts, but with less freedom than in the 

 preceding case; and lastly, the most delicate ramifications are 

 spent upon the cortical or yellow matter of the acini, without 

 penetrating to the brown. t 



Bichat, Meckel, &c. + Mappes, J. F. Meckel, loc. cit. 



