Mr. Beale on the Anatomy of the Liver of Vertebrate Animals. 467 



liver is now placed in soft cloths to soak up the water, and after 

 some hours it will be found to have diminished much in volume, and 

 to have a clayey consistence. The ducts are now empty, and may 

 be injected with a carefully prepared prussian-blue injection, to 

 which a little alcohol has been previously added. The mixture is 

 to be well stirred, and after having been carefully strained, it is 

 slowly and cautiously injected into the duct. Plain clear size is 

 next thrown into the portal vein, until the liver has become fully 

 distended with it in every jmrt. Lastly, a little plain size is in- 

 jected into the duct, the vessels carefully tied, and the liver placed 

 in cold water until the size has set, when very thin sections can be 

 readily obtained with the aid of a sharp knife. The author has tried 

 many other plans of injection, but the above has afforded the most 

 satisfactory results. On one occasion a human liver was success- 

 fully injected with four different colours ; the portal vein with flake- 

 white, the artery with vermilion, the duct with prussian blue, and 

 the hepatic vein with lake. 



Evidence of the existence of a tubular basement membrane in which 

 the liver -cells are contained. 



Not unfrequently liver- cells are set free with shreds of delicate 

 membrane attached to them, and this can sometimes be seen to be 

 prolonged either way in the form of a narrow tube. 



In certain specimens which have been exposed for some time to 

 the action of dilute soda, the walls of the cells appear to be dis- 

 solved and the tubes are seen to be occupied with a highly refractive 

 mass, and their outline is rendered very distinct. 



When portions of the cell-containing network are placed in strong 

 syrup or glycerine, exosmose of the water occurs, the diameter of 

 the tubes is much diminished, and their outline becomes distinct, 

 but uneven, in consequence of the shrunken state of the tubes of 

 the network. 



At the edge of a very thin section of liver sti*etching between two 

 capillary vessels, a very thin membrane, recognizable only by the 

 granular matter adhering to it, can sometimes be seen. 



The tubes of the network can be distended to a great extent by 

 injection, so that the walls of contiguous tubes meet, while the 

 capillary vessel between them becomes so compressed as not to be 

 recognizable. 



The injection often forms a sharp line towards the capillary ves- 

 sels on either side of the tube in which the cells lie, and gradually 

 shades off towar'^^ the centre of the tube. 



The cells which escape into the surrounding fluid from injected 

 specimens often have portions of injection adhering to them. 



If a section be made at right angles to the intralobular vein, the 

 cells are seen to form lines radiating from tlie centre towards the 

 circumference of the lobule, as authors have before described. 

 These lines of cells are really tubes of basement membrane, com- 

 municating with each other at intervals by narrow branches. In 

 injected specimens the walls of the tube can be demonstrated, and 

 are seen to be distinct from the capillary vessels. 



