One day `` . . . When the zookeeper wasn't looking, Marvin . . . Slipped out.'' The adventuresome ape proceeds to sample the delights of the city, going to the art museum, the movies, and a ball game. In the thickly painted caricatures of New York, Marvin, riding the subway or ordering the jungle fruit platter in a restaurant, is both amusing and surprisingly at home. The humor turns on the fact that big city dwellers rarely look at one another. Children will be in on the joke, which makes them smarter than the police, the zookeeper, and the other people. However, the minimal text does not make the most of the idea. Usually one line placed in the center of a blank page facing the picture, the narrative tends to define the illustration rather than enhance or extend it. These pictures are lively enough to need no definition. In a not unexpected twist to the end, back at the zoo, Helvetica the hippo dashes out when the keeper's head is turned. While Marvin is a sly blend of ape and human, the purple hippo is not as immediately believable, but who knows . . . If she buys a nice flowered dress, she will probably fit right in with the other ladies out for an afternoon of shopping. While not a necessary purchase, this will nevertheless produce a few chuckles. --Karen James, Louisville Free Public Library, KY Copyright 1992 Reed Business Information, Inc.