The relation in plants between fructification and innutrition (or rather, between fructification and such diminished nutrition as makes growth relatively slow) was long ago asserted by a German biologist--Wolff, I am told. Since meeting with this assertion I have examined into the facts for myself. The result has been a conviction, strengthened by every inquiry, that some such relation exists. Uniaxial plants begin to produce their lateral, flowering axes, only after the main axis has developed the great mass of its leaves, and is showing its diminished nutrition by smaller leaves, or shorter internodes, or both. In multiaxial plants two, three, or more generations of leaf-bearing axes, or sexless individuals, are produced before any seed-bearing individuals show themselves. When, after this first stage of rapid growth and agamogenetic multiplication, some gamogenetic individuals arise, they do so where the nutrition is least;--not on the main axis, or on secondary axes, or even on tertiary axes, but on axes that are the most removed from the channels which supply nutriment. Again, a flowering axis is commonly less bulky than the others: either much shorter or, if long, much thinner. And further, it is an axis of which the terminal internodes are undeveloped: the foliar organs, which instead of becoming leaves become sepals, and petals, and stamens, follow each other in close succession, instead of being separated by portions of the still-growing axis. Another group of evidences meets us when we observe the variations of fruit-bearing which accompany variations of nutrition in the plant regarded as a whole. Besides finding, as above, that gamogenesis commences only when growth has been checked by extension of the remoter parts to some distance from the roots, we find that gamogenesis is induced at an earlier stage than usual by checking the nutrition. Trees are made to fruit while still quite small by cutting their roots or putting them into pots; and luxuriant branches which have had the flow of sap into them diminished, by what gardeners call "ringing," begin to produce flower-shoots instead of leaf-shoots. Moreover, it is to be remarked that trees which, by flowering early in the year, seem to show a direct relation between gamogenesis and increasing nutrition, really do the reverse; for in such trees the flower-buds are formed in the autumn. That structure which determines these buds into sexual individuals is given when the nutrition is declining. Conversely, very high nutrition in plants prevents, or arrests, gamogenesis. It is notorious that unusual richness of soil, or too large a quantity of manure, results in a continuous production of leaf-bearing or sexless shoots; and a like result happens when the cutting down of a tree, or of a large part of it, is followed by the sending out of new shoots: these, supplied with excess of sap, are luxuriant and sexless. Besides