Experiments on growth and inhibition. I.—The increase of inhibition with distance

Abstract

In etiolated decapitated pea seedlings, single developing leaves inhibited axillary buds that were 70-100 mm. below them more strongly than similar leaves in similar seedlings inhibited buds at 5-15 mm. below them. Also in decapitated pea seedlings, single developing leaves retarded 2 buds below them, but retarded the more distant the more strongly. It is hence concluded that the strength of inhibition increases with distance. It is shown that, though axillary buds normally grow to a certain length before they are arrested, yet they are susceptible to inhibition during their early growth as well as later. For after extirpation they are rapidly formed again in the lower axils of decapitated pea seedlings, but not in those of intact seedlings. It is concluded that at first they are not inhibited because they are too close to the developing leaves. They therefore grow until they reach a distance below these leaves at which inhibition is strong enough to stop them.