Where Barbara Silverberg's Phoenix Feathers (KR, p. 820, J-272) tracked the elusive parallels between the zoology of myth and science fiction, Yolen's quest is an open-ended one and she bags an odd lot of mutations (see Curtis' title story "Zoo 2000," Guy Endore's "Day of the Dragon" and Howard Fast's "Mouse") and a cageful of extraplanetary exotica — such as the oversized, gravid space cow examined internally (a la Fantastic Voyage) by William Morrison's "Country Doctor," the giant moths in John Baxter's "Apple" and the Theodore Sturgeon's lovable, deservedly famous "Hurkle. . ." A solid, if somewhat old fashioned collection; however, few libraries need any more specimens of Hurkles, Arthur Clarke's "The Deep Range," or Thurber's "Interview with a Lemming," not to mention Norton's ubiquitous "All Cats are Gray.