HEMIBAS1DII. 



Ill 



In Tilletia, Entyloma, Neovossia, Tuburcinia, the brand-spores germinate 

 and form basidia-like conidiophores with spindle-shaped conidia ; their niy- 



FIG. 98. Tuburcintn. 1. T. trientalis. Hyphse, some of which bear conidia at the apex, 

 forcing themselves out between the ep-'dermal cells on the under side of the leaf ; 320 times 

 natural sue. 2. T. trientalis. A ball of spores in which some of the individual brand- 

 spores are about to germinate ; 520 times natural size. 3. T. primulicola : various forms 

 of conidia (500 times natural size). 



celium, on the other hand, produces later only single, sickle-shaped conidia, so 

 that two kinds of conidia are found, as in a few Basidiomycetes. In some 

 species, e.g. Ustilago hordei, the 

 brand-spores only germinate 

 vegetatively and form a myce- 

 lium. In nutritive solutions (so- 

 lutions of dung, etc.) where they 

 live as sapropltytes, the brand- 

 spores of many species emit 

 germ-tubes, and on these, yeast- 

 like conidia are produced by 

 repeated budding, which grow 

 into mycelia only when tbe 

 nutritive solution is exhausted. 

 These conidia have not the 

 power of producing alcoholic 

 fermentation. The very numer- 

 ous conidia, which are found 

 in the dung of herbivorous ani- 

 mals, are probably the yeast- 

 conidia of Brand-Fungi. The 

 brand-spores, which are eaten 

 by animals with the grain and 

 hay, pass into the dung and 

 without doubt give rise to a 

 very rich multiplication of 

 yeast-conidia. 



The couidia (also called 



FIG. 99. Vftilago. 1. Formation of brand- 

 spores. 2. Germinating brand-spore of U. peren- 

 nans. 3. Germinating brand-spore of 17. cardui 

 (after Brefeld). 4. U. fdiformis. a A brand-spore 

 with developed basidium ; b another, with a coni- 

 dium ; c with two conidia ; d with two conidia 

 placed diametrically opposite to each other ; e, de- 

 tached conidia which are growing into hyphse. 



