CLASSIFICATION OF THE TRUE FUNGI. 



11' 



ripe, but the germinating tubes only continue to grow when 

 they can penetrate into the stomata of the leaves of grasses. 

 Here the original my- 

 celium, with its uredo- 

 spores, is then developed, 

 and thus the peculiar 

 cycle of development of 

 this fungus is completed. 



Along with the aecidia 

 another fructifying ap- 

 paratus, the spermogonia, 

 always occurs ; these are 

 small jug-like capsules, 

 which project by prefer- 

 ence on the upper surface 

 of the leaves, and shed 

 their spores even before 

 the ecidia are ripe ; the 

 germination of these 

 spores has not yet been 

 observed. 



In some uredineas all 

 three generations occur 



on the same host. In Fig> 7. Bust of grain, 



many rust fungi one or ^> Puccinia graniinis. A portion of the 

 ,1 i basidiuni with uredospores ( /) and 



two of the chief genera- a teleutospore (<) X 390. 



tions are absent. When they only possess the teleutospore 

 stage these spores germinate as soon as they are ripe, and com- 



TT* _ ^^/i 



Fig-. 8. 



A, JScidium berberidis. Section through a thickened portion 



of the leaf containing Eecidium flasks (a) and spermogonia (sp.) 

 At a the under surface of the leaf. 



B, section through an aecidium in a young condition. 



