Most of the eight traditional horse stories collected here for YA readers are reprinted from popular adult magazines where they are unlikely to have caused much of a stir. From the Saturday Evening Post there are Colin Lofting's ""Last Bronc,"" in which a rodeo pro returns to his dad's ranch and to Elinore, the formerly ""skinny, freckle faced kid"" who has been waiting, and William Brandon's ""Chiltipiquin"" about an old Mexican of the lovable rogue variety and his devotion to a colt through whom his misdeeds catch up with him. The Ladies' Home Journal is represented with Stuart Cloete's ""Throw Your Heart Over,"" which makes a play for readers' hearts with brave Helen, whose love for her new mare saves her from polio, and poor but devoted Johnnie, her father, who is saddled with all the bills. There are loved horses who die or must be killed, one who loses faith in his then heartbroken master and another who saves his from a forest fire (""Now was the time for the blood of his Arab ancestors to prove itself""), and Fenner ends with Jack Shaefer's ""Jeremy Rodock"" -- and his obsessed revenge on the horse thieves who crippled his mares. Competent slicks for the susceptible.