Pools, riffles, and point bars are common bed forms in straight and meandering channels. Inflections in meandering channels correspond to riffles in straight channels. Both of these forms are shoals that are symmetrical across the channel for a short distance. Pool-riffle spacing appears to be independent of channel pattern, and as straight reaches merge with meandering reaches no change occurs in the spacing, form, or symmetry of the pools and riffles. Meandering processes which result in increasing channel length may result in the addition of new pools o t keep spacing constant. A five-stage model is proposed to explain the development of alluvial channels. The model is based upon channel morphology, channel morphometry, and qualitative conclusions based on numerous field observations.