In the former experiments the comparison between the respiration rate of the leaves of paulownia tree infected with witche’s-bloom and that of the healthy ones was made. The difference in RQ found between them indicated that the metabolism of the former was of an abnormal. But it was left behind to discuss the RQ abnormality obtained in the experiments with diseased leaves because of the anaccuracy of the measuring apparatus. This experiment was carried out in order to determine RQ more accurately. RQ was determined by the Warburg micro-manometric method. In this experiment the disks of the leaves of the third leaf order were used. The results are as follows; (1) The ratio between fresh weight and dry weight of the diseased leaves is about 11 per cent smaller than that of the healthy one. (2) Qo_2(quantity of oxygen consumption) of the diseased leaf disks is about 17 per cent greater than that of the healthy ones per dry weight and 30 per cent greater per area. Qco_2(carbon dioxide production) of the diseased leaf disks is 50 per cent greater than that of the healthy ones per dry weight and 65 per cent greater per area. These results correspond with what obtained in the author’s past work and the energy consumption of the diseased leaves seem greater in quantity than that of the healthy one. (3) RQ of the diseased leaves is about 0.94 and that of the healthy ones 0.74. The small RQ of the healthy leaves, for less than 1 the theoretical paulownia leaves. Since the organic acidal crystals are found in the petioles in a fairly large quantity. RQ of the diseased leaves is greater than that of the healthy ones. This corresponds with the results obtained in the author’s past work. The difference in RQ between healthy and diseased seems to be attributed to the abnormal metabolic conditions of the diseased leaves. (4) In the atmosphere of nitrogen instead ot air the diseased leaves produce carbon dioxide about 0.09mm per mg. dry matter, while the healthy leaves almost nie. (5) From these results it is supposed that the respiration of the diseased leaves, though composed mainly of aerobic respiration, is carried out to some extent unaerobically. Possible explanations for the greater RQ of the diseased leaves compared to that of the healthy one will thus be given. The respiration comparison of the diseased and healthy leaves is assumed as follows. RQ_d=Q’co_2+Q^Nco_2
Qo_2 > Qco_2
Qo_2=RQ_h RQ_d: RQ of the diseased leaves. RQ_h: RQ of the healthy leaves.