Of all the chimpanzees being taught to ape human language behavior, Sarah's ""reading and writing"" with her colored plastic symbols is probably the most impressive. The author, whose husband David Premack devised and ran the experiments with Sarah, was herself a trainer in the project and had her own interest in its application to the teaching of language-impaired children. This is a popular account of man's association with chimpanzees, beginning with earliest observations and including home adoptions as well as Washoe's mastery of the sign language of the deaf. Scholars might be impatient with Premack's references to unspecified ""experts,"" and skeptics might question that the poker-chip tokens used by Wolfe's subjects at Yerkes represented ""something far more advanced than simple association."" However, no one can help being amused at how man's anthropocentric definitions of language have retreated as subhumans were found first to convey information (bee dances), then to manipulate arbitrary symbols (Wolfe's poker chips), and finally, in the person of Sarah, to think of absent objects, master sentence patterns, and understand conditional propositions.