title: Host Alternation of Spruce Broom Rust.
abstract: Repeated inoculations demonstrate that Peridermium coloradense A. & K. is the gametophytic stage of Chrysomyxa arctostaphyli Diet., previous reports notwithstanding. Thus C. arctostaphyli is eliminated as the only familiar exception to Transhel's law, which may apply universally to microcyclic rusts.
authors.forename: R S
authors.initials: RS
authors.lastname: Peterson