528 



COMPARATIVE MORPHOLOGY OF FUNGI 



septa into two daughter cells, each of which cuts off a basidiospore without 

 a sterigma. The next cell below then swells and repeats the process 

 basipetally. The basidiospores germinate with germ tubes or sprout 

 conidia. S. albidum, on dead twigs in Ecuador, has true four-celled 

 cruciate basidia. 



Fig. 350. — Sirobasidium Brefeldianum. Habit, enlarged, showing basidia. (X145; 

 after Moller, 1895.) Sirobasidium albidum. 2 to 5. Development of basidia. (X250; 

 after Lagerheim and Patouillard, 1892.) 



Whether these two species are related to each other and are rightly 

 placed in the same genus, can only be decided by their cytological rela- 

 tions. Moller (1895) considered them as transition forms between the 

 Phragmobasidiomycetes and the Autobasidiomycetes, which latter had 

 developed from the former by a change in orientation of the basidial walls. 



