by Atheneum, $9.95. Mr. Johnson’s short stories differ in setting, subject matter, and even in style, but they are basically united. With a single exception, they derive from what one character describes as “the same primordial feeling of thrownness that every Negro experiences when hurled into a society that simultaneously supports . . . and annihilates him, because he can find reflections of himself nowhere in it. . .“ The author, who is black, plays brilliant variations on that provocative theme..