F1 hybrids between 2 inbred lines inherited the higher growth rate of one parent as a complete dominant, and owed their size-heterosis (dry weight, after 70 days, 4 times that of heavier parent) solely to a bigger "capital" of primordia in the embryo. Lindstrom''s evidence that the F1 shows an increased growth rate in a later stage does not explain size-heterosis on that basis in the grand period of growth, and his data on the effect of decreasing the "capital" of a hybrid by cutting off its leaves above the growing point are irrelevant to the author''s data on the effect of "capital" in terms of meristematic tissue in the embryo.