UROCYSTIS. 319 



and is destroyed during spore-formation, so that the balls of 

 spores are found in large cavities in the host-tissue. 



In the spore-masses the enveloping companion-cells are more 

 transparent than the spores proper. The latter germinate^ easily 

 in water, and produce promycelia which grow towards the air. 

 On the extremities of these several conidia arise, and, without 

 becoming detached, proceed at once to give off short conidio- 

 phores with termijial conidia. As this process is repeated 

 indefinitely, chains of conidia are formed. Fusion of conidia 

 never occurs. 



U. Kmetiana Magn. Magnus- describes this as destroying 

 and tilling with black spore-powder the ovaries of Viola tricolor 

 (var. anrnsis). 



U. filipendula Fuck, occurs particularly on petioles and leaf-ribs of 

 Spiraea FiUpendula. Brefeld found the spores germinating after a year. 



U. (?) italica (Sacc. et Speg.). In seed of Castanea vesca. 



U. purpurea Hazsl. Ovaries of Dianthus deltoides and D. prolifera in 

 Hunuarv. 



U. (0 coralloides Eostr. In roots of Turritis glabra in Denmark. 



U. orobanches (Pr.). In roots of Orohanche. 



U. (0 monotropae (Fr.) In roots and stems of Monotropa in Belgium. 



U. Johansonii ( U. Junci. Lag.). In leaves of JinicuA filiformis in 

 Switzerland. 



Tuburcinia. 



Spores forming lialls as in Urocystis, but all are equally 

 capable of germination. The spore-aggregations form large or 

 small, slightly thickened spots and crusts, which do not cause 

 very marked deformation of the host. Germination results, as 

 in Tillctia, in the formation of a promycelium bearing a tuft 

 of conidia at one end. White conidia are also produced from 

 the mycelium on the host-plant. 



Tuburcinia trientalis (Berk, et Br.)^ (Britain and U.S. 

 America). Plants of Trientalis europaea attacked by this fungus 

 are conspicuous in early summer by their swollen dark-coloured 

 stems and their smaller lighter leaves, which fall prematurely. 

 The conidia appear as a white mould-like coating on the lower 



iPrillieux, Bullet, de la Soc. hotan. de, France, 1880; and Brefeld (loc. cit.). 

 Heft XII. 



-Miignus, Xaturforsch. Fr. d. Pror. Brandenhttrg, xxxi. 



■'\Yoronin, Senckenberfj . naturforsch. GeselL, 1881. Plates I., II., III. 



