XI. Experimental researches on vegetable assimilation and respiration.—No. II. On the paths of gaseous exchange between aerial leaves and the atmosphere

Abstract

That individual cells within the substance of all plants conduct the gaseous exchange necessary for their metabolism by diffusion through their proper cell-walls must be beyond doubt, and that the exchange of gases between a water plant, as a whole, and the surrounding liquid is of the same nature seems as indubitable. When, however, we consider land plants, it becomes less obvious in what way or ways the continuous exchange of gases between the plant and the atmosphere is effected. The epidermis of such plants is covered with a more or less well-developed cuticle, through which specialized openings, stomata, occur with varying distribution and frequency. In maturer parts the epidermis and its cuticle may be replaced by suberised tissue, and the stomata by less specialized openings, the lenticles.