Another effect resulting from the collaboration of spatial peri city and tem- poral periodicity is a pattern like that in Figure 8. The autocatalytic activator u(x, is distributed periodically along the growing edge on a certain time interval. Then the concentrations of u(x, turn very low throughout the growing edge for a period of time. No pigment production takes place in this time interval until the periodic state of u(x, reemerges. A temporal oscillation between these two states creates this pattern.