The Effect of Subjecting Peas to Air Enriched with Carbon Dioxide: I. THE PATH OF GASEOUS DIFFUSION, THE CONTENT OF CO2 AND THE BUFFERING OF THE TISSUE

The intake of oxygen by an isolated pea was shown to be entirelythrough the micropyle; the loss of CO₂ was about two-thirdsvia the micropyle and the rest through the cuticle. The internalatmosphere of a pea in air contains about 11 per cent CO₂ v/v. Peas transferred from air to CO₂ in air mixtures required nearly24 h for their internal CO₂ content to come to equilibrium.The increase in internal CO₂ content was found to be balancedby a decrease in the content of malic acid and the pH of thetissue changed little. On return to air the changes were reversed.Slices of cotyledons in water apparently maintained their pHby loss of cations rather than change in malate content.