(1)In the present paper, the writers described the results of experiments and investigatins on the relation of "Akiochi-phenomenon" and the occurence of Helminthosporiose on rice plant, particularly on the change of phosphorylase activity during the process of plant growth.
(2)In the plant tissues, phosphorylase activity was found in every part of plant, except epidermis, vessel, sclerenchyma and motor-cell.
(3)Significant difference of phospholylase activity between the resistant and the susceptible varieties of rice plants cultivated on "Akiochi" regtin had not been mentioned. However, those palnts grown in "Akiochi" -region, showed weaker activity in earlier stages than in those which were grown in ordinary place. On the other hand, the occurence of Helmin thosporiose increased accompanying with the decrease of phosphorylase activity.
(4)It seems likery that phosphorylase activity decreased in the tissues around the lesions caused by means of inoculation with Cochliobolus miyabeanus.
(5)Although the starch which was accumulated around the diseased spots on leaves disppeared when these leaves were put in dark places, obvious changes had not been observed in the permeability of cell-membrane sround the spots comparing with that of in normal tissues.