320 



BOTANY. 



for a few species only.* In all which have been examined 

 the spore sends out apromycelium, which is generally short 

 and jointed, and upon this several sporidia are produced, 

 much as in the Uredineae. In Tilletia caries the promyce- 

 lium produces a tuft of slender branches (Fig. 224, li), which 



FIG. 221. 



FIG. 222. 



FIG. 223. 



Fig. 221 .Spore-formation in Ustllago Maydis. a, the end of a spore-f orming hy- 

 pha containing i row of young spores ; b, another spore-forming hypha, containing 

 two young spores ; o, a spore nearly ripe, still surrounded by the gelatinous mem- 

 brane of the hypha. X 1800. After Fischer von Waldheim. 



Fig. 222. Spore-formation in Ustilaqo antherarum. a. an ieola.'x'. gelatinous hy- 

 pha, with the contents distinctly breaking up at the lower end a portion not yet 

 broken up ; b, a number of gelatinous hyphae fused into an irregular mass, showing 

 the formation of ninny spores ; c, a spore nearly ripe, still surrounded by the gelat- 

 inous hypha membrane, also a young spore upon a lateral branch, a and o X 1800 ; 

 b x 900. After Fischer von Waldheim. 



Fig. 223. Formation of " solitary spores" in Sorispoi ium Saponarice. a, hyphae 

 with two yonng spores ; b, a spore at a later stage ; c. hyphse with spores in differ- 

 ent stages of development; at c' a thin wall has formed around the contained pro- 

 toplasm as in b ; at c" the wall is much thicker, and at c"' it is still thicker, x 300. 

 After De Bary. 



have been seen to unite laterally by a kind of conjugation 

 (not, however, of a sexual nature, in all probability) ; from 

 these branches (called by some writers " secondary spores ")f 



* According to Fischer von Waldbeim, the germination of the fol- 

 lowing species is known, viz., Tilletia caries, T. Lolii, Ustilago an- 

 therarum, V. flosculorum, U. carbo, V. destruens, U. Maydis, IT. recep- 

 taculorum, U. longissima, U. Vaillantii, Urocystis pompholygodes. 

 Uroc. occulta. 



f De Bary calls these branches sporidia, and what are here called 

 sporidia, he calls secondary sporidia. 



