1. Unilateral destruction of globus pallidus does not influence natural conditioned reflexes. Bilateral destruction results in temporary disappearance of natural as well as artificial conditioned motor reflexes. Further training is necessary for the reestablishment of these reflexes. However, the training period is twice that required in the preoperative period. Reestablished conditioned reflexes manifest themselves with long latency. Movements are performed with accuracy but very slowly. 2. After partial bilateral destruction of the pallidum, animals that have been trained not only to press a pedal, but also to make a choice between a right or a left feeding tray, lose the latter ability. After the reestablishment of conditioned reflexes, the animals make a correct choice of side only 50–70% of the time. 3. After total bilateral destruction of globus pallidus, the animals lose artificial conditioned reflexes; these are not reestablished even after four months of training, though natural conditioned reflexes can be reestablished but with great difficulty.