232 DISEASE IN WILD MAMMALS AND BIRDS 
Congestion of the liver is a matter of small importance 
from the standpoint of pathology unless it be of sufficient 
duration to cause cyanotic atrophy and induration. How- 
ever the facts that congestion of this organ occurs three 
times as often in the mammal as in the bird and that 
vascular cirrhosis has not been seen in the latter class, 
are interesting and noteworthy. In addition ascites of 
hepatic origin has not been seen in the birds. The expla- 
nation for this lies in the rich anastomosis between the 
intestinal area and the caudal vena cava so that the blood 
does not have to pass through the liver to reach the heart. 
This arrangement would reduce the back pressure in 
passive congestion and relieve the liver in the congestion 
due to toxic or inflammatory distention of small vessels. 
Cirrhosis. 
The chronic inflammations or so-called cirrhoses of the 
liver have been subjected to a great deal of study and 
many theories have been expounded as to their cause and 
classification. Here is not the place to discuss the aca- 
demic question of nomenclature but rather to adopt an 
acceptable worldng classification and to analyze our 
material thereon. A cirrhosis is a chronic inflammation 
of the liver indicated by increased connective tissue with 
evidences of degeneration and attempts at regeneration 
on the part of the hepatic cells. Certain cases of increased 
connective framework fail to show the last two features 
and, since they must be grouped near the cirrhoses because 
of the prominence of connective tissue, they are called 
fibroses, perilohidar in type. Among the instances carry- 
ing out the full stipulations are livers ^^dth evidence 
of a perivascular fibrosis and obstruction, to which are 
added degeneration and regeneration of the lobular 
margins; such are portal, cirrhoses in human medicine 
associated with passive congestion in the intestinal area, 
and ascites. In a second variety, fibrosis seems to succeed 
upon obstruction to the biliary lumina or upon peribiliary 
