MORPHOLOGICAL CHARACTERISTICS OF CERATOCYSTIS ULMI (BUISM.) C. MOREAU IN AMERICAN ELM TREES

摘要

Observations on the development ofCeratocystis ulmi(Buism.) C. Moreau show that the fungus produces large numbers of spores (microspores) as small as 0.5ensp;mu; in diameter in the xylem of American elms (Ulmus americanaL.). The development of microspores has been followed from their germination into fine, short hyphae to their formation endogenously and exogenously in association with mature hyphae and spores.