THE ultimate structure in vegetation is determined by dominance, and dominance is based on the ability of the individual to respond to its environment. No two plants arc exactly alike in their demands : each plant has its special growing-place. The indigenous forests in general carry a single dominant that largely determines the physiognomic features of the formation-the tawa or rimu, or white pine, or kauri, or totara, or southern beech. In forest development we recognize succession, and dominants appear to mark each phase in the .succession : thus we have the manuka dominance, bracken fern,. the indigenous induced hard fern, piripiri dominance, wineberry, mahoe, five-finger dominance, progressing to rewarewa, hinau, or kamahi dominance. In the tussock grasslands we see the same rise to dominance according to growing-place- the fescue tussock, the poa . tussock, the danthonia tussock ; and in the depleted lands of the South Island we see the scabweed dominant under the influence of the rabbit. In the artificial grasslands of New Zealand the trend to dominance is well observed - the rye-grass, cocksfoot, brown-top, Danthonia eilosa, .D. semiannzclaris, ratstail, paspalum, tall fescue, prairie-grass, floating sweetgrass, and Poa aquatica dommance respectively.