The idea that carcinoma originates in a single area is borne out in the case of carcinoma of the bladder. Furthermore, carcinoma beginning in the tissues of the bladder usually remains confined to these tissues. Only in rare instances does it metastasize to distant regions or extend beyond the confines of the bladder and perivesical tissues. Death occurs indirectly from the effects of carcinoma of the bladder but directly from secondary infection in the surrounding tissues and in the kidneys. Because of the tendency for carcinoma of this organ to remain local, it should especially lend itself to radical resection, and the results of radical surgical treatment in these cases should be better than they are at present. The functioning mechanism of the bladder depends on the sphincter muscles controlling the outflow, the ureteral orifices through which the urine enters the bladder, and, in operations on the bladder, a sufficient