``Each day is more painful than the last. And each day I am more happy,'' writes Donald Hall from the Pittsburgh Pirates' spring training camp of 1973 in his essay collection Fathers Playing Catch With Sons (North Point Press, San Francisco, $13.50). The book is not entirely about baseball -- there are essays on basketball, table tennis, and football -- but it is infused with a love of sport, of the games men and boys play. A sentimental and sincere and very good book; the essay on baseball poetry is particularly interesting. You look at the fish. You notice that the ``body is moderately deep and slightly compressed laterally, the scales are small, the mouth is large with the upper jaws ending just ahead of the midpoint of the eye,''and it's about four inches long.
Since you are in a cool, clear stream with a gravel bottom in Tennessee, you can now identify the fish as a Rosyside Dace. You will be able to do all this if you happen to have Thompson's Guide to Freshwater Fishes (Houghton Mifflin, Boston, $9.95), in which Peter Thompson lists field marks, size, color, habitats, natural history, and local names of 113 species. Illustrations are four-color and lovely.