314 



USTILAGINEAE. 



epispore, and the clusters appear black or leaden-grey. Ger- 

 mination as ill Enftihiina. 



Melanotaenium endogenum (linger) (Britain). This is 

 found on Galium Mollugo and G. verum. The niyceliuni 

 permeates the whole intercellular system of the host, and is 

 nourished by large tufted haustoria. 

 The host-plants remain small, with 

 shortened internodes, shrunk leaves, 

 and undeveloped flowers. The 

 spores occur in patches in de- 

 formed flowers, and on leaves and 

 internodes. They are formed in 

 summer, and by autumn are capable 

 of germination in water ; Woronin 

 could not keep them alive over 

 winter. On germination a bifur- 

 cate promycelium is produced, one 

 branch of which remains rudimen- 

 tary, while the other grows on, 

 and, if long, becomes divided by 

 cross-septa. At its apex, a number 

 of conidia arise, and, after many of them have fused in pairs, 

 they germinate directly to a septate filament into which the 

 plasma passes over (Fig. 171). 



Mel. caulium (Schneider) causes the stem of Linaria imlgaris to swell 

 up like a quill. 



Mel. cingens (Beck.) on Linaria genistifolia. According to Brefeld, 

 this species only germinates after resting for four years, whereas Juel 

 easily caused Mel. caulium to do so after a short rest. 



Fio. 171. — Mclaaotatiiiuin endo</citvm. 

 Germinating spores. One has already 

 produced a promycelium with a whorl of 

 five branches, of which two have fused. 

 (After Woronin.) 



Urocystis. 



Spores massed into balls, consisting of several spores sur- 

 rounded by smaller companion-cells incapable of germination. 

 The central spores are clearly distinguished from the others 

 by their larger size, darker colour, and thicker coat. The balls 

 of spores are developed inside coils of hyphae, which become 

 entwined together and swell up in a gelatinous manner. The 

 central spores on germination give rise to a promycelium, with 

 terminal conidia which do not as a rule fuse in pairs, Init grow 

 out directly into mycelia. 



