gradually from its broad base to its slender tip, according to some law of decrement specific to the plant; and any alteration in the relative velocities of longitudinal and transverse growth will merely make the leaf a little broader or narrower, and will effect no other conspicuous alteration in its contour. But if there once come into existence a node, or ãlocus of no growth,ã about which we may assume the growthãwhich in the hyacinth leaf was longitudinal and transverseãto take place radially and transversely to the radii, then we shall
at once see, in the first place, that the sloping and slightly curved sides of the hyacinth leaf