IntroductionThat a certain antagonism exists between vegetative growth and reproduction seems still to be the rather prevailing opinion among students of plant development. Luxurious vegetation is thought to be detrimental either to the initiation of gametes or to their union, resulting in a conspicuous absence of seeds and fruit, while a limited vegetative growth is considered to be the precursor of marked reproductive activities. In many instances this apparently is true. The facts, however, do not permit one to accept such a view as an axiomatic generalization, for careful analysis of the development of many plants leads to a diametrically opposite conception.Both empirical and experimental evidence leave one hardly room for doubt that only too frequently a clearly recognizable association does exist between excessive vegetation and lack of fruitfulness on one hand, and diminished growth and abundant seed formation on the other. The question is, however, which in this relationship is cause and which is effect; for our present knowledge of correlation, both quantitative and qualitative, between the various parts or organs of higher plants compels one to accept the existence of a causal relationship.Data may be marshalled showing the effects of growth on reproduction, but there is also ample proof of exactly the reverse situation. Plants belonging to all three groups-annuals, biennials and perennials-supply a large number of examples where it is clearly evident (1) that vegetative growth is almost quantitatively determined by the developing seeds and fruit; (2) that it often decreases at the exact time and in the exact proportion to the amount of flowers formed and seeds set; and (3) that the rate of vegetative growth is controlled by the developing fruit. These conceptions, though quite contrary to a current point of view, do not appear to be overdrawn. Because of the sequence in time, vegetation usually preceding reproduction, and because of the greater economic importance of

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