APPENDIX. 233 



Entyloma, De By. 



Mycelium of very tliin branched filaments, the ends of which 

 are transformed into spore- bearers. For the formation of 

 the spores these parts are swollen and divided by transverse 

 partitions; spores rounded polyhedric, of a clear yellowish- 

 brown, usually with a thick membrane composed of two 

 distinct layers. 



Entyloma Ungerianum, De By. {Prolomyces microsporus, 

 Unger.) At first in the form of rounded patches, later as 

 brownish-yellow swellings ; spores variable in form, polyhedric, 

 with a thick double membrane more or less verrucose. — On the 

 leaves of Ranunculus Ficaria. 



TiLLETIA, Tul. 



Spores spherical, isolated, granular or reticulated, proceeding 

 from delicate branched threads ; rarely smooth. 



* Spores with a granular epispore. 



Tilletia bullata, Pckl. Mass of spores blackish, in roundish 

 buUate spots ; spores globose ('OIS-'OIG mm.), brown ; epispore 

 granular. — On leaves of Dock, Bumex. 



»* 



Spores with a reticulated epispore. 



Tilletia caries, Tul. Bitnt ; included within the sermen ; 

 spores spherical, rather large, black. — On Wheat, filling the grains 

 with dark-coloured spores, fetid when crushed. Autumn. Very 

 common. (Plate V. figs. 84-91.) 



PERONOSPOREI, De By. 



Pekonospoua, Casp. 



Parasitic threads mostly inarticulate. Spores of two kinds : — 

 1. Acrospores on the tips of the branchlets ; 2. Oospores 

 large, globose, on the creeping mycelium. 



Peronospora infestans, Mont. Potato Mould ; threads 



