While some anglers will approach the idea that there are scientific factors that determine why fish bite- or do not bite, few fishermen will read this without learning a good deal of the why, when, how of fishing- and the biological facts that a scientist who is also a practical fishermen shares. He approaches some of the liabilities and the assets of fishermen generally, in realistic fashion. He discusses the known factors in the biology of fish as to sight, color sense, hearing and feeling, smelling and tasting, the behavior patterns, the variations with species. He then goes on to external factors:- temperature and temperature changes, atmospheric pressure, the seasonal character of water in lakes and ponds, shallow vs deep lakes; streams and rivers, oceans, bays and estuaries. The maps of the homes of the various kinds of fish he feels are essential equipment; he stresses some of the under utilized fishery resources. Then he goes on to the art and science of fishing itself, the factors having to do with ""why fish bite""- and the knowledge behind selection of bait or lure. Finally -- taking in turn fresh water and salt, he applies the scientific and the practical know-how to more than two dozen fish. Final sections suggest what to do when the fish are caught, preparation for cooking or for freezing and a few recipes that he has found popular.