In her third picture book about bear cubs Oliver and Ronald, Bach paints such a nasty picture of sibling rivalry that one feels she's carrying on some battle of her own. It begins like other moral tales, with hero Oliver suffering before he can triumph; here caring for sick, grouchy Uncle Otto is indeed a trial. When he's had all he can take, Oliver arranges a switch with Ronald, who, deliberately inept, pretends to be Oliver--all the while filling Uncle Otto's tired ears with praises of Ronald, who surely deserves to inherit his Uncle's books, globe, and maybe even cabin (for a library). But the grouchy old bear, who isn't dying but has been busy planning his will for years, can't be fooled. . . and so he ends up announcing that the non-bookish Oliver will get the globe and head the bears' public library to be created from the books and building. Anyone whose sympathies have been with Oliver till now might well be lost, however, by the gleeful little victory dance that Ronald's comedown inspires. The peculiar lesson Uncle Otto intends to teach Ronald is of ""the bad side of smart,"" which ""grew into snappish, a first cousin to mean,"" in his own case. But it's a questionable association, and a spiteful performance all round.