Stomatal Movement and Photosynthesis in Pelargonium. Ii. Effects of Water Deficit and of Chloroform: Photosynthesis in Guard Cells.

This paper describes the second half of a series of tests of the photosynthetic theory of stomatal movement. A corollary of this theory is that any agent that inhibits photosynthesis should prevent opening or cause closure in light-unless some other action prevents this. It has been reported that this relationship does not hold either in wilting or under the action of chloroform (WILSON, 14). The effects of these factors are investigated in the present paper. As before (11), stomatal aperture was measured by means of a modified porometer method, photosynthesis by infrared absorption, and, except in a few experiments, the leaf material all belonged to the same clone of Pelargonium zonale var. Barney.