USTILAGO. 297 



are about 20m in diameter, and form in water promycelia with 

 conidia. In nutritive solutions Brefeld found conidia produced 

 in large numbers, and multiplying by yeast-budding. The 

 promycelial cells grow out as septate branched twigs, from 

 which conidia are abjointed, and after coalescing in pairs, produce 

 germ-tubes. 



Ust. violacea (Pers.).^ Carnation-smut (Britain and U.S. 

 America). In Silene, Viscaria, Saponaria, Bianthus, Stellaria, 

 Malachium, Cerastium, and Lychnis, the pollen sacs of other- 

 wise well-developed flowers become filled with dark-violet 

 spores, which escape and discolour the other floral parts. 

 Pistillate flowers of Lychnis attacked by this fungus develop 

 stamens containing the smut-spores (p. 27). On germination 

 in water, promycelia of three or four cells are formed, and 

 become detached from the spores. Primary and even secondary 

 conidia are produced, while coalescence of promycelial cells and 

 conidia is common ; but only a few of them produce germ- 

 tubes. In nutritive solution, according to Brefeld, everything 

 proceeds much more vigorously; from tiny conidiophores on the 

 promycelia numerous conidia are produced in succession, and 

 from these other conidia are budded off like yeast-cells till 

 nutriment fails, when they gTow out to form hyphae. The 

 conidia are longer than those formed in the water-cultures, 

 and coalesce in pairs to give rise to longer and stronger 

 germ-tubes. 



Ust. holostei De Bary on Holostsam mnhellatum. The host-ovaries 

 become filled with spores which germinate to four-celled promycelia from 

 which pairing sporidia are formed. 



Ust. Duriaeana Tul. In the ovary of Cerastium. 



Ust. major Schroet. On Silene Otites. The spores germinate only in 

 nutritive solutions. (Britain.) 



Ust. seminum Juel. In the ovules of Arahis petraea in Scandinavia. 

 The spores on germination produce simple hyphae. 



Ust. entorrhiza Schroet. In root-cells of Pisum sativum. 



Ust. pinguicolae Rostr. On Pinguicula vulgaris in Denmark. 

 According to Brefeld, the spores germinate equally in water or 

 nutritive solutions, forming three-celled promycelia, which separate 

 from the spore and bud off conidia from each cell. 



^Tulasne, .4nB. d. sciences natur., Ser. iii.. Vol. vii., 1847. 

 Atkinson (American Carnation Society, 1893), describes this and other smuts 

 frequenting American Carnations. (Edit.) 



