Elizabeth Shepherd, who traced Tracks Between the Tides (KR, 1972), discovers the world of the mummichog minnow through the eyes of young Adam and Steven who are lucky enough to see a pair of the fish mate and be on hand when the eggs hatch days later. Adam and Steve's conversations are filled in by an ebullient narration of the mummichog's unobserved life underwater (""Snap! snap! snap! The baby mummichog eats a crusty isopod. . .""), and an impressive volume of facts (on fish in general and minnows in particular) is delivered in suitably simple form. It's too bad that the mummichogs' common names (mud dabbler, chub, gudgeon) aren't mentioned earlier on. Even once the mummichog's identity has been cleared up this will still be most useful to youngsters who have the opportunity to duplicate Adam and Steven's observations firsthand.