By a double colchicine treatment the nerve-cell population of hydra was reduced to less than 1% of the normal complement. Such severely nerve-depleted hydra contained normal or higher than normal concentrations of head activator, head inhibitor, foot activator and foot inhibitor which in normal animals are produced by nerve cells. According to typical chromatographic properties all four morphogenetic substances were chemically identical to those found in normal animals. It is suggested that in nervedepleted hydra the epithelial cells, as the only remaining cell type, have taken over the morphogen-producing function of nerve cells.