61 



DIGESTIVE TRACT. 

 CIRRHOSIS OF THE LIVER. 



It was a matter of surprise to find well-marked cases of hepatic; 

 cirrhosis in rats, as this disease in man has been pretty generally 

 regarded as very largely due to intemperance in the use of alcoholic 

 beverages. Such an etiology hardly accounts for the condition in the 

 rat. The lesion is by no means rare; well-marked cases are encount- 

 ered probably as often as once in a thousand rats. We have never 

 seen it in a young rat, probably because the condition develops slowly 

 and the rat reaches adult life before the process is complete. The 

 organ is usually somewhat yellowish, very firm, often, but not 

 always, somewhat shrunken in size. The surface of the whole organ 

 is covered with small, rounded elevations; a typical " hobnail-liver " 

 in miniature. 



Microscopically we find various degrees of increase of connective 

 tissue. In a well-marked case the capsule is much thickened, and 

 heavy bands of connective tissue run through the organ in every 

 direction. This increase of connective tissue is most marked in the 

 vicinity of the portal vein and its companion vessels. The micro- 

 scope will show that in some fields over half of the structure is made 

 up of fibrous tissue. The liver cells that remain appear to be normal. 

 The presence of animal parasites in the liver is frequently associated 

 with a considerable hypertrophy of the connective tissue of the 

 organ. In a majority of cases of hepatic cirrhosis, however, no 

 parasites are to be found. One case has come under observation in 

 which the surface of the liver was covered with a number of flattened, 

 wart-like elevations. Upon section nothing was to be found to 

 account for this except an enormous overgrowth of connective tissue. 



FATTY DEGENERATION OF THE LIVER. 



A considerable number of cases of well-marked fatty degeneration 

 of the liver have been seen. At times the fatty change is so extensive 

 that the organ floats when placed in water. Microscopically the liver 

 cells are found to be extensively infiltrated with fat granules. 



HERNIA. 



A few ventral herniae have been observed. In the majority of the 

 cases the sac contained intestine only and this was easily reduced. 

 On two occasions other viscera have been found in the sac; the spleen 

 on one occasion and in another case along with several loops of 

 intestine which were easily reduced there was found the upper 

 extremity of the right division of the uterus which carried a cyst 

 about 1 centimeter in diameter. The cyst was partly adherent to 



