New York, Doubleday, 1954. Hardback first edition and first impression. Near fine. The jacket has a little bumping and rubbing to the spine tips and top edge, otherwise in decent shape. Signed by the author "Hal Clement / (Harry Stubbs)", review slip laid in. Provenance: from the collection of George Locke; author, publisher, dealer, bibliographer and collector. Best known for his Spectrum of Fantasy reference material and Ferret Fantasy.