Diurnal Fluctuation in a Physical Property of Leaf Cuticle

THE extent to which the outer surface of a leaf is wetted by water may depend on factors varying with species, age, and position on the plant. A series of investigations on advancing contact angles has made it clear that, in addition, the adhesion of water for leaf surfaces may vary considerably with the condition of the leaf, and, in particular, with factors showing a cyclic diurnal change.