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TEXT-BOOK OF FUNGI 



compound, upright stem; usually the tips of the com- 

 ponent hyphae become free from each other near the apex 

 and spread outwards, bearing either single or chains of 

 conidia at the tips, the whole structure resembling a sheaf 

 of wheat in miniature. 



FIG. T-^o.Cercospora apii. i, a celery leaf attacked by the 

 fungus ; 2, conidiophores bearing long, slender, hyaline, septate 

 conidia. Fig. i, nat. size; fig. 2, highly mag. 



Many of the species are yellow, some red, others pallid, 

 some again are dingy and blackish. 



Many of the species of Isaria are known to be conidial 

 forms of ascigerous fungi belonging to the genus Cordyceps^ 

 which is remarkable for being parasitic on insects and 

 spiders. Inoculation takes place during the life of the 

 insect^ which continues to live until the mycelium spreads 



