The Developmental Origin of Stomata Pattern in Crinum

This work deals with measurements of interactions between stomata and the determination of their pattern of distribution. A method was developed for measuring the relation of stomatal frequency to the distance from randomly selected central stomata. The deviations of this frequency from random values are a clear indication of the distances to which the presence of a stoma is correlated with the occurrence of additional stomata in its neighborhood. In Crinum americanum two stomata do not occur less than a certain minimum distance from one another, and there is no effect of a stoma which extends over greater distances. The first stages of stomatal development occur in neighboring cells, and the minimum distance was found to be the result of the orderly, determined development of the guard cells together with some of the other epidermal cells. These results thus show that the simple pattern of stomatal distribution of Crinum is not the result of interactions between the stomata, and they demonstrate the use of methods which should have general validity for the study of stomata and similar patterns of differentiation.