Rats lesioned in the septal area showed significant increases in bar pressing for food on both continuous and FI schedules of reinforcement. Although the septal-lesioned rats showed significant increases in water consumption, their food intake was not significantly different from sham-operated animals, except during the first 5 postoperative days and during the initial 3 days of post-operative deprivation. The data were interpreted as indicating that septal-lesioned rats are hypersensitive to unconditioned and drive stimuli and that this is expressed in their operant and conditioned performances. © 1969.