Cortically lesioned, intact, and hippocampally lesioned albino rats were given posttrial injections of strychnine sulphate (1.0 mg/kg or 0.33 mg/kg) or saline. Animals with hippocampal lesions showed deficits in Lashley III maze-habit acquisition but not simultaneous visual discrimination. No retention deficits of postoperatively learned maze habits were observed even after long intervals. Hyperactivity in subjects with hippocampal lesions could not adequately account for deficits in maze performance. Posttrial injection of strychnine had no effect on learning. The data suggest that hippocampus is involved in formation, but not storage, of memory traces. Consolidation of traces was neither facilitated nor attenuated by strychnine.