of colorless appressoria in an albino mutant of Colletotrichum lagenarium. Can. J. Microbiol. 28: 1210-1213.Spores of an albino mutant of Colletotrichum lagenarium formed colorless appressoria. The appressoria germinated laterally and formed secondary appressoria after further incubation. Appressorial formation was accompanied by nuclear division and migration of the spore contents into the primary appressorium. When the primary appressorium was mature, the nucleus in the spore had disappeared and the spore appeared empty. Similar phenomena were observed in the formation of secondary appressoria from primary appressoria. Formation of both primary and secondary appressoria was temperature sensitive. When spores were incubated in the presence of cycloheximide after 1 h of incubation, formation of primary and secondary appressoria was not affected. Secondary appressoria pigmented by addition of 3,4-dihydroxyphenylalanine could penetrate nitrocellulose membranes. SUZUKI, K., Y. KUBO, I. FURUSAWA, N. ISHIDA et M. YAMAMOTO. 1982. Behavior of colorless appressoria in an albino mutant of Colletotrichum lagenarium. Can. J. Microbiol. 28: 1210-121 3.Les spores d'un mutant albinos de Colletotrichum lagenarium forment des appressoria incolores. Les appressoria germent latkralement et forment des appressoria secondaires aprks une incubation prolongCe. La formation des appressoria s'accompagne d'une division nuclkaire et le contenu des spores Cmigre dans l'appressorium primaire. Lors de la maturation de l'appressorium primaire, le noyau dans la spore disparait et la spore apparait vide. Des phCnomknes semblables ont Ct C observCs lors de la formation des appressoria secondaires i partir des appressoria primaires. La formation des appressoria primaires et secondaires est sensible i la tempCrature. La formation des appressoria primaires et secondaires, n'est pas affectke lorsque les spores sont incubCes en prksence de cycloheximide apks une heure d'incubation. Les appressoria secondaires qui forment des pigments par l'addition de 3,4-dihydroxyphknylalanine peuvent pknCtrer des membranes de nitro-cellulose.[Traduit par le journal]