An inquiry into the reasons for the existing low survival rate in cases of infiltrating carcinoma of the bladder has disclosed four cardinal causes of failure with any method of treatment: (1) preexisting metastases; (2) preexisting extravesical extension; (3) intercurrent complications, and (4) incomplete destruction or extirpation of the primary growth. It therefore seems obvious that accurate evaluation of the efficacy of any treatment in the total eradication of primary infiltrating tumors will depend first on the exclusion of metastasis and extravesical extension. The clinical application of our recent pathologic observations1to each individual patient now permits the exclusion or recognition of metastasis and extravesical extension in a fairly high percentage of cases and indicates the prognosis in most instances. In 1944 the late Dr. Hugh H. Young proposed to me an analysis of the 1,400 cases of carcinoma of the bladder in the files of the Brady Urological