In the former reports (33) the authors affirmed in soybean plant, as other plants (1, 13, 23, 29, 31, 32, 37, 38, 41'), the one grown on drought spot has higher osomtic value than the one grown on moist place. But they observed that the temporary drought resistance, which acquired on extremely dry spot in hot season, relaxates in cool season. Fortunately some of these samples were studied to see the regulation of osmotic value by subjecting them to wilting. Temporary wilting is believed to give the plant drought resistance (16, 42), like the temporary cold resistance (30,31,35,39,40).Whether the experience of former drought, which has influenced to increase the cell sap concentration (6, 7,34,36,43) still effects osmotic ascension or not on the part produced from the growing point after the soil moisture is regained is a problem not yet investigated. Material and MethodsThe material is a autumn-soybean Tamanishiki which is the same in Rep. 1. The plants were grown in cyrindric, galvanized iron pats 15 cm in diameter and 17 cm height. The soil used was sandy loamm and the saturated water capacity of this soil was estimated approximately 26%. A watering tube containing crushed stone extended down the side of each pot to the bottom. The pots were divided into two groups of 80% and 50% of water capacity, and the pots were weighed daily and adjusted by watering. The pot of 80% water capacity which had been subjected to wilting stopped being watered, and in several days it reached near the point of permanent wilting. After that the soil was once more watered to regain the optimum soil moisture, 80% of water capacity. The results (Fig. 1) are described in the former report (33).

Fukuda and present writer (1952) reported that the osmotic value in soybean plants increased gradually as the plants grew and the maximum value appeared at the podding or at the ripening season.But the drop of osmotic value and also that of transpiration were observed at the beginning of flowering. But we could not determine whether the falling of osmotic value at flowering was affected by the external factor which caused the drop of evaporation as well as transpiration, or by the internal factor which directly affects the variation of osmotic value. The factor which affects the osmotic variation of plants is the seasonal succession of enviromental factors4' 6) and the growth periods2, 3, 6,7) , Fukuda's opinion' is that season means for the plant the change of meteorological conditions and periods of growth.To analyse these two factors which affect osmotic variation, the present writer used soybean plants (Glycine hispida) as before . Two varieties, mid-season and late-season, were planted at the same time twice in the year. If in the same growth period of two varieties under different meteorological conditions, a similar periodical variation of osmotic value appears, the variation may depend on growth period.

The effect of short day treatment on flowering was already studied by many investigators. According to So et al6> the increase of cell sap concentration and * Problem of physical and physiological dryness. Rep. 17 by Y. Fukuda ;

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