9 2 



TEXT-BOOK OF FUNGI 



On germination the oospore gives origin to a stout promy- 

 celium-tube containing the protoplasm and the sexual 



FIG. 29. Urocystis occulta, one of the Ustilagineae. 

 i, upper part of a rye plant attached by the fungus ; 2, 

 clusters of spores, one of which has germinated and pro- 

 duced a cluster of secondary spores ; 3, a spore that has 

 germinated and produced secondary spores, two of which 

 have produced tertiary spores, a. Fig. j, reduced; the 

 others mag. 



nucleus of the oospore. This nucleus by two successive 

 karyokinetic divisions forms four nuclei. These four nuclei 



