Inhibition of Regeneration in Two-Headed or Two-Tailed Planarians

Abstract

Two-headed or 2-tailed planarians were produced by longitudinal splitting. After amputating 1 of the duplicate parts but leaving a stump, regeneration of the removed part took place. If, however, the duplicate part was removed close to the common origin of the duplicate parts no regeneration took place. Such inhibition is explained as "due to the presence in appropriate proximity and relations of the equivalent of the structures which had been removed.".