264 Explmiaiion of Plates. 



PLATE LI. 



(All Figures x 500 unless otherwise stated.) 



UROCYSTIS. 



Fig. 



186. Section of wheat, .stem affected by Urocystis tritici, showing the cavities partially 



filled with spores . . . . . . . . . . . . X 20 



187. Spore-balls of Urocystis occulta from Poa caespitosa. 



188. Spore-balls of Urocystis tritici from wheat. 



189. Spore-balls of Urocystis occulta from Rye grown in Germany. 



190. Spore-balls of Urocystis stipae. 



191. 192. Germinating spores of Urocystis tritici from wheat. 



