110 



HEMIBASID1I. 



chiving its growth, until it reaches that part of the plant where 

 the spores are to be formed. The spore- formation takes place in 

 the same way in all those species whose brand-spores are deve- 

 loped in the floral parts of the host-plant. Many Brand-Fungi have, 

 however, a more local occurrence, and the mycelium is restricted 

 to a smaller area of the leaf or stem. Those organs of the host- 

 plant in which the brand-spores are developed often become 

 strongly hypertrophied. In perennial plants the mycelium winters 

 very often in the rhizome. 



The brand-spores are the winter resting-spores of the Brand- 

 Fungi. They arise in the tissues of the host-plant, which is often 

 destroyed, and become free through the rupture of the epidermis ; 



FIG. 97. Doassansia alismatis. 1. A fruit-body, formed by a covering of oblong 1 hypba% 

 which encloses a mass of brand-spores, and is embedded in the leaf-tissue of the host- 

 plant; 20 times natural size. 2. A germinating brand-spore, 500 times natural size. 3. 

 Three connected resting-spores, 400 times natural size. 4. Two conidia grown together, 

 600 times natural size. 



they are thick-walled, generally brown or violet, and very often 

 possess warts, spines, or reticulate markings. Fruit-bodies, that is 

 enclosed organs of reproduction, are found in few genera (Sphace- 

 lotheca, Graphiola ; Doassansia, Fig. 97). In Tolyposporium, Tiibur- 

 cinia, Thecapliora (Fig. 102), etc., the brand-spores are united into 

 a ball of spores. On germination the brand-spores behave as 

 cMamydospores, namely, as the fundament of conidiophores, by 

 emitting a short germ-tube, i.e. a conidiophore (" promycelium"). 

 The USTILAGINACE.E (Fig. 99, 2) have a short transversely divided co- 

 uidiophore, with laterally developed conidia (comp. the basidia of 

 the Protobasidiomycetes). The conidiophores of the TILLETIACE^: 

 are iindivided (unicellular promycejia), and bea,r the conidia ter- 

 minally, and so resemble the basidia of the Autobasidiomycetes. 



