58 



ELEMENTARY STUDIES IN BOTANY 



second, but the spores are formed at the ends of slender 

 branches that arise from a peculiar cell or group of cells 



FIG. 44. A lichen growing on bark ; the numerous dark disks are cup-like spore-cases. 



called the basidium (Fig. 41). These are therefore the 

 " Basidium-fungi " (Basidiomycetes) , and the wheat rust and 



FIG. 45. A lichen growing on a board. 



mushrooms are members of it. Any fungus in whose life- 

 history basidia appear is a " Basidium-fungus." 



