Chronic experiments on the albino rat have shown that two sets of postural adjustments, the placing and hopping reactions of Rade-maker, have a strictly localized cortical control. Removal of the rostral third of one cortex renders the legs contralateral to the removal completely deficient in respect to these reactions. No greater deficiency was found in unilaterally decorticate, thalamic, or decere-brate rats. Bilateral cortical removals produced deficiency of all four legs. When all the cortex except the rostral third of one hemisphere was removed the legs contralateral to this remnant responded normally. The fact that specific small remnants of cortex are capable of managing these reactions in normal fashion shows conclusively that their cortical representation is narrowly localized and functionally independent of all other cortical areas.