In a temperate pluvial climate, under conditions that favour episodic or seasonal high run-off though the annual rainfall is moderate, fine-textured relief (with high drainage density) may develop rapidly (feral at first, to become subdued later) as a result of first-cycle dissection of tectonic slopes or redissection of slopes that have been smoothed by the activities of frost in a glacial age. Under similar temperate pluvial conditions such textures may, however, develop also, though probably more slowly, in landscapes that have long ago become fully mature and even subdued, including some that have been subject to slow downwasting of the surface during a state of dynamic equilibrium. This change to fine texture and high drainage density may be brought about by a change in rainfall characteristics to those favouring high run-off, either epiwdic or seasonal (though a similar change may be attributable in some regions to the more pluvial conditions wming on in glacial ages). The reverse change, to coarser texture, if it comes about at all as a result of climatic changes in the reverse direction, must be much slower. Thus, at any rate in a region like New Zealand with a fast tempo of trosion, fine land'lape texture tends to prevail, but this is probably in some cases relict from a former climate.