_Catarrhal inflammation_ may result in thickening or calcification of the lining membrane of the ducts and bladder, with the accumulation of such quantities of thick tenacious mucus, as to become a source of impediment to the flow of the bile, and thus give rise to jaundice. Such inflammation becoming chronic in the common duct, may result in great dilatation of the gall-bladder, from the accumulation of bile. In many cases, this form of inflammation would seem to have originated in the duodenum, reaching the biliary passages by extension through the opening of the duct into the intestine. It may also result from the presence of calculi or parasites in the passages, or from inflammation of the liver. _Suppurative inflammation_ may attend different forms of fevers, or result from the presence of calculi. The gall-bladder, with the bile ducts, in such cases, may be filled with a purulent fluid, or the same may be found infiltrated through their walls. Perforation of the walls of the gall-bladder may result from this form of inflammation, with escape of contents into the peritoneal cavity, inducing thus fatal peritonitis. Fistulous communication may also form between the bladder and colon, duodenum or stomach, or through the abdominal walls, adhesions having first taken place between these parts. _Dilatation_, both of the bladder and ducts, may occur as a result of obstruction of the gall-ducts. That of the former may be very great, giving rise to a tumor that may be plainly felt through the abdominal walls. Dilatation of the ducts may involve either the common, or large hepatic ducts, or the smaller branches within the liver. Such dilatations may be sacculated in form, or general, involving the whole tube. Morbid Growths. _Cancer_ of the walls of the gall-bladder is not unfrequent, and may be either primary or secondary. The cavity of the bladder may in this way become obliterated, and the common duct obstructed, thus inducing jaundice. In a case examined for the Drs. Pettingill, the gall-bladder was as large as the fist, from scirrhus cancer; its cavity obliterated; adhered to the pylorus to which the disease had extended; and the bile ducts greatly dilated and filled with a large quantity of puriform fluid. The patient had been for many months extremely jaundiced. _Fibroid tumors_ are very rarely observed in connection with the gall-bladder. _Tubercular deposits_ may be found beneath its peritoneal covering. =Biliary Calculi.= The presence of biliary calculi, or gall-stones in the gall-bladder, or some of the ducts, is a very common occurrence. These bodies are composed of the elements of the bile, largely however of cholesterine, sometimes in an almost pure state, in others, more or less mixed with inspissated bile. In many cases, a nucleus of nearly pure cholesterine will be surrounded by a deposit of biliary matter mixed also with scales of cholesterine.