Epidermal Water Content Research Articles

Stomatal Movement and Epidermal Water-Content

PROF. D. THODAY has suggested1 that the remarkable stomatal behaviour of coffee may be explicable on a hypothesis involving variations in the water content of the epidermis as distinct from that of the leaf as a whole. As he says, a critical experiment would be the determination, in saturated air, of the relation between stomatal aperture and radiation. This has not been done.

Stomatal Movement and Epidermal Water-Content

IN a recent paper, F. J. Nutman1 has described the behaviour of the stomata of the coffee plant and directed attention to their remarkable sensitiveness to insolation. Within three minutes of exposure to direct sunlight the stomata begin to close, even though the water supply is abundant. Moreover, the closure is reversible: shading a single leaf on an insolated plant results in opening of the stomata of the shaded leaf. This is quite outside the normal range of stomatal behaviour hitherto described.