110 PRACTICAL MICROSCOPY. 



quently gets bat an imperfect notion of the plan of the human 

 organ. 



Pieces of liver, say one-half inch square by a quarter of an inch 

 thick, are hardened by twenty-four hours' immersion in strong alco- 

 hol. Larger pieces may be prepared with Miiller's fluid. Sections- 

 should be cut with a microtome, care being taken to include the trans- 

 verse division of some of the medium-sized portal canals. The portal 

 vein, with its accompanying vessels, may be easily distinguished from 

 the solitary and less frequent branches of the hepatic veins. The ele- 

 ments of these canals, and especially the larger ones, are best kept 

 intact by infiltration of the tissue with celloidin; but very fine sec- 

 tions may, with care, be made from the alcohol-hardened tissue. 

 Even free-hand cuts, after some degree of skill has been obtained by 

 practice, will answer very satisfactorily. Stain with haema. and 

 eosin. 



SECTION OF LIVER OF PIG. CUT VERTICALLY TO AND 

 INCLUDING THE CAPSULE OF GLISSON. 



(Fig. 79.) 

 OBSERVE: 



(L.) 



1. The capsule of Glisson 0. (Note the prolongations sent into 

 the organ, which divide the entire structure into irregularly polyg- 

 onal, if divided transversely; and elongated, vertically sectioned areas 

 the hepatic lobules.) 



2. The central (intra) veins C V. (Note that the figure formed 

 by. the division of the vein varies according to the direction of the 

 cut, a circle, oval, or elongated slit, as the lobules have been sectioned 

 transversely, obliquely, or vertically. ) 



3. The hepatic veins H V. (Those shown in the section are un- 

 doubtedly sublobular. It must be remembered that sub applied to 

 these vessels is misleading, as the lobules are situated on every side, as 

 well as above the sublobular veins.) 



4. The portal canals P C. (Even the smaller ones, I, are readily 

 differentiated from areas containing hepatic veins, inasmuch as a 

 group of vessels can be distinguished the hepatic veins running solus* 



5. The portal veins V. (Observe that they usually present as the 

 largest element of the canals. Note their thin walls, the same fus- 

 ing insensibly with the surrounding connective tissue. They not in- 

 frequently contain blood-clots, with deeply stained scattering white 

 corpuscles, appearing with this amplification as dots or granules.) 



6. Hepatic arteries A. (The larger examples may be determined 

 by their thick muscular media and the wavy pink line the fenestrated 

 membrane. Several may be seen in a single canal.) 



