[Effect of actinomycin D and cycloheximide on planarian regeneration after repeated amputation].

A Planaria deprived of its head twice at an interval of a few days can regenerate in the presence of actinomycin D, even if the second amputation takes place 13 days after the first one, but it cannot regenerate in the presence of cyclohemixide. This indicates that at the moment of the second amputation, stable RNAs are available for regeneration in the tissues behind the level of section, whereas proteins have to be synthesized in situ in the blastema.