title: Reply from I.p.f. Owens and R.v. Short.
authors.affiliation: Institute of Zoology, Zoological Society of London, Regent's Park, London, UK NW1 4RY; Galton Laboratory, Dept of Genetics and Biometry, University College London, London, UK NW1 2HE.
authors.forename: I P
authors.initials: IP
authors.lastname: Owens
authors.forename: R V
authors.initials: RV
authors.lastname: Short