Studied the exact mnemonic span of a number of individuals for visual and auditory digits and the effects of increasing the presented series beyond this span. 165 college students, in groups of 8 to 14 persons in each group at different hrs, were used for testing. For auditory tests, a series of digits were given by means of a silent pendulum, invisible to the Ss. A similar series was presented for the visual tests. The results were scored by counting the number of digits which were correct in form and position. The average span was approximately 8.2 digits during the visual mode of presentation and 7.7 during the auditory mode. An increase in the number of digits exposed beyond the number of the span, resulted in a more extended distribution of individuals and decreased the number of digits that could be recalled. Two types of individuals were observed. (PsycINFO Database Record (c) 2006 APA, all rights reserved)