Quantitative studies were made upon the rays of three species of Compositæ, viz. Arnica unalaschensis in Mt. Hakkoda, Astertrinervius var. congestus and Asteromæa indica var. pinnatifida in Aomori. In the Arnica, on account of its single-headedness, the difference of flowering season, together with the meristic change of rays, was determined by the external conditions, but in the latter two, the internal factors seemed to have played the principal rôle on it, and in the Aster no seasonal fall was seen in the first one month. The series of Fibonacci hold some stability in the appearance of mode, and the occurrence of variates on some classes is more improbable than on other classes.