

THE PARENCHYMA OF THE LITER 169 



stained nuclei give the ducts marked prominence even with the 

 low -power. Indeed, the smaller portal canals are frequently dif- 

 ferentiated by this element alone this being especially true when 

 the structures have been disturbed, and perhaps torn, in the. pro- 

 cess of mounting.) 



8. The lobular parenchyma. (The arrangement of the hepatic 

 cells, forming branching columns, is merely indicated with the 

 low -power by their deeply stained nuclei presenting granular 

 areas within the lobular boundaries. Still, by careful attention, 

 the elements will be seen to radiate more or less distinctly from 

 focal points the central or intralobular veins. 



(H.) 



9. The portal veins. 



10. The lymph-spaces in the connective tissue of the portal 

 canals. (Note, in those which are better denned, the nuclei of the 

 endothelium. Do not confound these lymphatics with small veins, 

 as the latter present a tolerably denned wall, while the lymphatic 

 chinks appear like rifts in the connective tissue; it would be diffi- 

 cult to make this distinction without the endothelial cells.) 



11. Hepatic arteries. (On account of its solidity, the liver 

 will enable the student to secure sections of blood-vessels present- 

 ing the typical structure more nearly than the specimens obtained 

 from the organs heretofore examined.) Note (a) the elongated 

 nuclei of the muscular elements of the media; (&) the fusing of 

 the adventitia with the connective tissue surrounding the artery ; 

 (c) the sharply defined outer boundary of the intima the fe- 

 nestrated membrane, which, from the action of the hardening 

 agent, has contracted the elastic fibers and detached (d) the 

 endothelial cells. (Inasmuch as the lining cells of small arteries 

 are very frequently partly detached in alcohol -hardened tissue, 

 they may simulate columnar cells. A like appearance is often 

 presented when an artery has been sectioned obliquely, by the 

 projecting muscle-cells of the media.) 



12. Hepatic ducts. Note : (a) The lining cylindrical cells. 

 (&) The nuclei of these cells (as a rule, perfectly spherical ; and, 

 in transections arranged in a circle, affording an appearance per- 

 fectly characteristic). (c) Mucous glands in the wall of the 

 larger ducts, lined with large, nucleated, columnar cells, preeisely 

 like those lining the duct-lumen ; and, hence, liable to be mis- 

 taken for small ducts. (The tube carrying the mucus secreted in 



