In a black-white discrimination problem a group of rats that was required to jump an 8 1/2-inch gap placed 4 ins. in front of the doors learned significantly more rapidly than a group without a gap. Jumping a gap placed behind the doors, that is, after an overt response had been made to the doors, had no effect on the rate of learning. A group required to jump a gap placed 15 inches in front of the doors was greatly retarded in comparison with a group that jumped a gap 4 ins. from the doors, but not retarded in comparison with a group that had no jump. The accelerative effect of the jump is believed to be due to the pause it necessitates, which gives opportunity for longer stimulation and tends to prevent headlong responses, and to the state of enhanced responsiveness to stimuli that results from the obstruction, annoyance, and fear of the gap and jump.