If 'Genesis' were a photo essay; Wilderness Rivers of America, By Michael Jenkinson. New York: Harry N. Abrams.

Watch a child play outdoors after a rainstorm, and you observe one of Earth's fundamental wonders. If the runoff lasts long enough the young human can be absorbed for hours sending twigs down miniature torrents, following the cutting and rebuilding of toy canyons and sandbars.

There is something primeval and fundamental about a river. Rivers are one of Earth's key signatures. Their channels and left behind on Mars; but a channel is not a river any more than a hoofprint is a zebra. There may be acid rivers on Venus; but sulphuric acid flowing is not a river (on Venus or industrial New Jersey).

The long linkage of man and river has many roots. Commerce leading to civilization is one. So the Nile, Rhine, Danube, Mississippi, Volga, and Yangtze are fixed in the history of the race. But there is another link: of man the explorer, awed by rapid and canyon; lulled by gentle meandering among meadows; eager to discover around the next bend the tributary, the horsetail fall cascading down limestone cliff, the trout pool, the osprey nest, the log shared by painted turtle and orange dragonfly. It is to that instinct that Michael Jenkinson and 11 superb photographers devoted themselves in this magnificent book.

The result could be sneered at as yet another coffee table book. But it's something more. Three decades ago Rinehart (later Holt, Rinehart & Winston) produced a series of histories of American rivers, one of which (on the Rio Grande) won a Pulitzer. Buf for all their hundreds of thousands of words those valumes failed to capture the wonder of the streams they charted. Jenkinson, in this collection, has avoided that loss. His essays are spare, somewhat impressionistic, but tell the essential of the history, flora, fauna, and route features. No whitewater expedition could plan its course by the description, the rudimentary maps or the photos. But any river-runner would be awed by both the grandeur and the intimacy of the photographs. Plate after plate gives one a hint of what it might have been like to look in on the Earth before man's arrival. One photo in particular, of limpid sunlight flooding down a majestic green valley of Alaska's Noatak River, could stand as a visual metaphor for the Seventh Day of Genesis.

Any enterprise that must select runs the risk of not including favorites. The Green, St. John, Rogue, and Stanislas are not here. Perhaps they are not wilderness enough. But the Noatak, Canada's Fraser, Idaho's Salmon, the Colorado (Grand Canyon), Rio Grande, Buffalo, Boundary Waters of Minnesota, Atchafalaya, Allagash, upper Hudson, and Suwannee are included.They present a rich assortment of scenes: tumultuous, sluggish, arctic, tropic, expansive, secret -- but above all pristine.