The Effects of Colchicine and Auxin on Rhizoid Formation of Dryopteris erythrosora

The effects of naphthalene acetic acid and colchicine on the rhizoid formation in Dryopteris spore were described. The results obtained are summarized as follows:1. In contrast with the case of Equisetum spore, the formation of rhizoid is prevented greaty in the medium containing NAA. That is, NAA-treatment of the germinating spores prevents the formation of rhizoid from the spore, but rather promotes it from the protonema.2. The position of the rhizoid initiation is very irregular in the spore cultured in the medium containing NAA.3. The frequency of occurrence of the rhizoidal protonema is higher in the case of the colchicine treatment.The author wishes to express his hearty thanks to Prof. T. Shimamura who kindly examined the manuscript of the present paper.