Exp. I. It was the problem whether the growing small tillers check the ripening process in fruitful stems or not in wheat. 1) From the results, the average weight of heads, 1, 000 grains-weight and total weight of grains were found to increase when the small tillers were cut or pressed down at the head-formation stage. The effect of cutting-off was especially remarkable. Exp. II. The purpose was to know of the interrelation between weak and strong tillers at the stage of vegetative growth in wheat by means of radiophosphorus. 1) At the tillering stage, P32 absorbed through roots were transferred in larger amounts to the weak tillers than to the strong ones. Among the tillers formed at the same time, the amount of P32 transferred was larger to the lower tillers than to the upper. P32 absorbed through leaf surface of either weak or strong tillers was transferred apparently more to the weak tillers. But, when P32 was absorbed through leaf, it was transferred more to upper tillers than to lower ones among the tillers growing at the same time. 2) At the head-formation stage, the translocation of P32 absorbed through both roots and leaf showed the same tendency as that in the case of 1). But the difference between weak and strong tillers was smaller. Therefore, it seems that the weak tillers seize nutritives away from the fruitful stems during the vegetative growth period checking the development of the latters.