THE LIVER. 223 



CHAPTER XVI. 



THE LIVER. 



Preparation 1. ITninjected liver. To prepare 

 sections of the liver small pieces are placed in 2 per 

 cent, bichromate of potash solution for ten days, 

 transferred from this to weak spirit, and in twenty- 

 four hours are placed in strong spirit, to complete 

 the process of hardening. The tissue will be hard 

 enough to cut thin sections from in another day or 

 two. The sections are stained with logwood, and 

 mounted in dammar varnish. They should be made 

 in two directions, viz. (1) in a plane near arid parallel 

 to one of the surfaces of the liver, and (2) vertical to 

 the surface. Those made in the direction first named 

 will for the most part cut the central or intralobular 

 veins across, those in the second direction may take 

 them along their length ; the apparent arrangement 

 of the blood capillaries and liver cells in the indi- 

 vidual lobules will differ, both, in accordance with 

 this difference of direction and also according as the 

 lobule is cut exactly through its centre or at some 

 part more or less removed from this. Between the 

 lobules are seen the branches of the portal vein, 

 always accompanied by a branch of the bile duct, 

 the columnar epithelium of which is very well seen 

 in these preparations, and by a branch of the hepatic 

 artery. All three are included in a mass of connec- 

 tive tissue, a prolongation of Glisson's capsule, en- 

 closing them in a so-called portal canal. In this 

 connective tissue cleft-like spaces may generally be 

 seen two or three in the section of a portal canal 

 not merely breaks in the connective tissue, but with 

 quite a definite wall. These are the accompanying 



