Free Space Characteristics of Barley Leaf Slices

Abstract

Measurements are described of free space content of barley leaf slices. It is shown that the leaf slices contain a Donnan free space of about 3 µ-equiv/g fresh weight of tissue at a concentration of 300 mN, together with a water free space occupying 0.21 ml/g fresh weight. The Donnan free space is shown to be located in cell walls, as in other tissues (beet discs, barley roots) but the water free space is largely due to cut or damaged cells, injected intercellular spaces, and surface films of solution. The results are discussed in relation to free space of intact leaves.