Sumimtary. The initiation of perithecia in the homothallic ascomycete Sordaria fimiiicola was completely suppressed, without seriously inhibiting vegetative growth, by growing the fungus on an agar medium containing one of the following additions: 1) 1 uM 5-fluorouracil, 2) 10 to 100 jum 6-azauracil, 8-azaguanine or 8-azaadenine, 3) 50 to 500 uM cyanide or azide, 4) 5 % (w/,v) casein 'hydrolysa...
