This is another of Emily Hahn's genially offbeat jaunts, a sort-of sequel to On the side of the Apes (1971) but with a larger purview. Unlike Flora Davis' equally diverting Eloquent Animals (p. 279), which concentrates on current animal communication research projects, Hahn first diddles around quite respectably among historical curiosities--Sullivan the Horse-Whisperer, Signor Tagano (Your Dog Can Write), the wolf children of Midnapore--and looks closely at Clever Hans, the mathematical wonder horse who hoodwinked countless scientists. (In both books, Hans is a constant referral, the ""Clever Hans syndrome"" the ultimate insult.) Like Davis, she has traveled around the country, consulting and visiting (instant rapport seems to be the nature of the beast), but there is reasonably little overlap, for Hahn clearly enjoys less academic types--zoo and circus folk--and includes information on Lilly's dolphins, several elephants, birds, horses, a savvy octopus, and a goose imprinted to a metal washtub. She also poses a stiff challenge to Chomsky's human-grammar argument, using evidence from those in close contact with animals, and alludes to. a Columbia University ape named Neam Chimpsky for ironic good measure. Look Who's Talking! will have lots of people listening--kind of a Clever Hahn syndrome.