144 



Minnesota Plant Diseases. 



merous intermediate conditions exist showing great differences 

 not only in the number of hairs but in the kinds produced. 



The spores are usu- 

 ally oval in shape 

 and s i n g 1 e-celled, 

 though some are 

 somewhat elongat- 

 ed and many-celled. 

 The explosive appa- 

 ratus for spore or 

 sac ejection has al- 

 ready been noted. 

 It is in the true cup 

 fungi that these de- 

 vices reach the 

 greatest degree of 

 perfection. Acces- 

 sory spore-forms are 

 not at all common. 

 The smaller forms 

 of the true cup fungi 

 abound on dead 

 sticks or dead stems 

 of herbaceous plants 

 or on the ground, 

 especially among 

 mosses, and are 

 often no larger than 

 a pin head. Many 

 grow on dung. The 

 stick inhabiting 

 forms are not usual- 

 ly brilliant in color, 

 though some are 

 lemon colored. Not 

 a few are parasitic. 

 Most of the largest 

 forms are saprophytes upon the ground or upon decaying tree 

 trunks or on dung, and are often very brightly colored. Some 



I'iG. 64.- 



-A cup fungus (Plicaria repanda) on the bark of 

 a fallen and decaying tree. Original. 



