Two tests of memory have been devised to measure the remembering ability of patients with severe memory impairment of organic origin. In this study, the patients were seniles with behavior disturbances sufficient to require hospitalization. One test permits measurement of memory defects of marked degree; the second test measures defects of lesser severity. The methods of giving and scoring the tests have been outlined in detail. It is important to emphasize that the values obtained by these methods are to be expressed in terms of the particular test used. For the present, at least, they must be considered as relative rather than absolute.