Minnesota Plant Life, 



79 



happened in the study of the rust-fungi, were supposed orig- 

 inally, by botanists, to characterize entirely independent plants, 

 but it is now known that the blue moulds and their relatives 

 the green moulds can, under suitable conditions of growth and 

 nutriment, produce the sac-fruit-bodies. Thus it is apparent 

 that in the ability to form such tiny orange-colored "truffles" 

 they are quite unlike the black mould which had no such ca- 

 pacity. The general plant-bodies of the different sorts of 

 moulds and their general life-habits are, however, very similar, 

 so that popularly they are all included under the same name. 

 Botanically, black moulds and blue moulds are quite distinct. 



