272 Explanation cj Plates 



PLATE LV. 



{All Figures X 500 unless otherwise staled.) 



TILLETIA FUSCA. 



Fig. 



219. Festuca bromoides with every spikelet smutted . . . . . . nat. size 



220. Spores of the same in surface view, showing raised ridges and gelatinous envelope. 



221. Spores in optical section. 



222. Spore germinating after 17 days in water on a slide, witli elongated bi-septate pro- 



mycelium bearing 7 conidia at its apex . . . . . . X 300 



