116 PRACTICAL MICROSCOPY. 



2. The hepatic artery A. (In the human liver, the portal canals 

 frequently carry a number of arteries and ducts, instead of one of each, 

 as shown in the one selected for the illustration. The arteries can 

 nearly always be differentiated by the clear wavy line of the fenes- 

 trated membrane. Should the section have been in a longitudinal 

 direction with reference to the vessel, look for the elongate nuclei of 

 the smooth muscle-cells of the media, some running with the artery 

 the longitudinal and others at right angles to its course the cir- 

 cular fibres.) 



3. The hepatic duct D. (Observe the thickness of the wall, 

 depending, of course, upon the diameter of the duct itself and the 

 presence of connective tissue supporting scattering non-striped 

 muscle-cells. Note the beautiful, clear, columnar cell-lining. 

 That these cells are polygonal in transverse section is demon- 

 strable at D L, where the duct has been cut in a longitudinal way, 

 and the cells are seen from above. 



4. The connective-tissue element of the canal, reaching out in 

 various directions between the adjacent lobules. 



5. Lymph spaces or chinks L. (Note the stained nuclei of the 

 endothelia.) 



6. Nerve trunks. (In the larger canals bundles of medullated 

 nerves may be frequently seen. They are not shown in the accom- 

 panying illustration. ) 



THE LOBULAK PARENCHYMA. (Fig. 82.) STAINED 

 CELLS FEOM HUMAN AND PIG'S LIVER. 



OBSERVE: 

 (H.) 



1. Isolated hepatic cells A, A. Note the large, variably 

 sized nuclei, their nucleoli, and the granular protoplasm of the 

 cell -body. 



2. Groups of cells forming portions of the hepatic cell-columns 

 as at C. 



3. Cells containing fat globules D. (This is not necessarily a 

 pathological process, although exactly resembling one, but the physi- 

 ological storing of hydrocarbons. ) 



4. Doubly nucleated cells, B. 



