Hyperplasia of the interstitial connective tissue of the liver, with secondary contraction, results essentially through the agency of irritating influences conveyed to the organ through the portal vein or the hepatic artery, possibly also through the bile-duct. These influences are principally either toxic or bacterial. Of the former, some are derived from without, as alcohol, lead and highly irritating foods. Bacteria may cause cirrhosis in part directly and in part indirectly, through the poisons they generate. Other toxic substances, generated in the intestines as a result of fermentative processes, or resulting from deficient functional activity of certain organs such as the liver, the kidneys, the skin, may also contribute to the development of hepatic cirrhosis. Sometimes no etiologic factor can be determined. As the irritating cause reaches the liver either through the portal vein or through the hepatic artery, the type of the resulting diseases will vary accordingly, with the