133 



1st. — Tlie hepatic artevy, which supplies it with nutrient blood. 



2nd. — The hepatic vein, which conveys venous blood back to the 

 heart. 



3rd. — The portal vein, or functional vessel, which brings the blood, 

 charged with absorbed material, from the stomach, spleen, pancreas, 

 and mesentery. From this latter source portions of the bile elements 

 are extracted, and the bile manufactured by the liver cells is then 

 carried by the biliary tubes to the gall bladder, and from thence by 

 the hepatic duct which opens into the small intestine, close to the 

 stomach. All animals, with the exception of the horse and rat, have 

 a bag, called the gall bladder, for the purpose of collecting and storing 

 the Bile, a viscid, greenish-yellow, and bitter fluid. Bile assists in the 

 digestion, and absorption of the nutrient material in the intestines, it 

 also increases the peristaltic action of the bowels. 



318. The liver is the largest organ of the body ; but, while frequently 

 the subject of a great amount of disease and disorder in human beings, 

 it is, happily, not nearly so subject to derangements in the domestic 

 animals. Like all other parts of the body, it is liable to inflammation. 

 The symptoms are not very well defined, and diagnosis has to be 

 arrived at by negative results. Such cases should always, therefore, be 

 entrusted to professional care. Occasionally, on making di post-mortem, 

 enormously enlarged livers are found, both in horses and cattle, 

 which the animals, when alive, gave no indications of such ailments 

 being present. Sometimes, however, these enlarged, or hypertrophied 

 livers are accompanied in the horse by dropsical swelling of the legs, 

 and shortness of breath ; while in cattle, the brisket, under side 

 of the neck, and lower jaw, become filled with a watery effusion. 

 This latter symptom is also seen in traumatic heart disease in cattle. 

 When cattle are heavily stall-fed with fancy foods, too highly seasoned 

 with aromatic flavouring, and containing an excess of amylaceous 

 matter, such as damaged rice, starch, sugar, &c., or where there is a 

 preponderance of carbonaceous over nitrogenous principles — in other 

 words, a badly balanced food — the liver is apt to undergo fatty 

 degeneration, or fatty infiltration. In the former, the liver cells become 

 changed into material of a fatty nature ; while in the latter, fatty 



