114 



SPECIAL HISTOLOGY. 



Fig. 219. 



composed of vessels, is introduced into the expanded head of 

 this tree, in such a manner that the larger vessels lie in the clefts 



between its principal masses, 

 the smaller and smallest, in 

 those between the subordi- 

 nate masses, ultimately pene- 

 trating into the lobules them- 

 selves, so that every lobule 

 is connected with many of 

 the finest twigs, receiving a 

 coat from the connective tis- 

 sue which accompanies them, 

 and we shall have as distinct 

 an idea as possible of the 

 relations of the vena porta. 

 The hepatic duct and artery 

 merely accompany the vena 

 porta and, therefore, require 

 no special notice. 

 In form, the lobes of the Pig's liver are angular, usually 

 presenting irregular four, five and six-sided figures in longi- 

 tudinal and transverse sections. 



In the human liver, but very little connective tissue accom- 

 panies the vena porta between the hepatic islets, and the latter 

 can neither be said to possess coats nor to be in any complete 

 manner enclosed by the vessels. In cirrhosis of the liver, on 

 the other hand, an enormous increase takes place in the amount 

 of connective tissue contained in the parenchyma of the liver, 

 and tire individual secreting segments may become prominent 

 or even form isolated lobules. The reddish brown hepatic 

 substance is softer, because more macerated, and sinks in more 

 than the rest, upon the surface and in sections ; it may also be 

 more easily scraped away and sometimes readily falls out in fine 

 segments. The cortical layer, which forms a reticulation around 

 the reddish brown spots, presents narrower places, fissura 

 interlobular es, Kiernan, and wider, spatia interlobularia, in which 

 not uncommonly a bloody point may be seen, arising from a 

 portal vessel, but not so regularly as in the brown spots, where 



Fig. 219. Portal vessel of the Pig, cut open, with its accompanying branches of 

 the hepatic artery and duct. After Kiernan. 



