TREMELLALES 



525 



conidia are produced (Fig. 344, 2). In Tremella, the conidia are spherical, 

 and may sprout in nutrient solution (Fig. 345, 3 to 7) . In Tremella lutescens 

 they are found in Nature on young, still felt-like fructifications where they 

 are cut off in large numbers on branched conidiophores (Brefeld, 1888). 

 In T. mesenterica they are replaced by uni- or binucleate oidia which result 

 from the breaking up of the terminal portions of hyphae (Fig. 345, 1 and 

 2) and multiply by sprouting (Dangeard, 1895). With the appearance of 

 basidia and the increase of gel secretion, conidial formation decreases and 

 their remains are imbedded in the gel. A similar succession was reported 



Fig. 346. — Protomerulius brasiliensis. Habit. (Natural size; after M oiler, 1895.) 



for Ditangium. A young fructification, which appears in the fall, 

 consists of a swollen hyphal felt whose mature top has crateriform open- 

 ings, covered by stratose, branched conidiophores (Fig. 344, 8). The 

 conidia resemble the basidiospores but are only half as large. During 

 the winter, the hyphal membranes swell, the fructification gelifies and 

 basidia appear. The basidiospores germinate without division either by 

 conidia or germ tubes. As far as known, the secondary spores formed 

 on the mycelium are uninucleate, those on the fructifications binucle- 

 ate (Neuhoff, 1924); hence the former are haploconidia, the latter 

 diploconidia. 



