CHAPTER XXIX. 

 FUNGI (Continued). 



THE SAC FUNGI, OR ASCUS FUNGI. 

 (Class Ascomycetes.) 



435. General characters. The mycelium is septate (divided 

 by cross walls into numerous cells), and grows either within the 

 substratum or upon the surface. In the latter case it often sends 

 branches, called haustoria, into the cells of the host, to obtain 



Fig. 231. 



A, a perfect fungus (Cordyceps militaris) parasitic on pupa of a moth. Head portion of the 

 fungus enlarged, showing fruit bodies (perithecia containing asci and spores. B, an imper- 

 fect stage showing conidiophores bearing white masses of conidia. 



nutriment. Many of the species are polymorphic, i.e., different 

 stages in the life history of the same species appear under dif- 

 ferent forms. Some of these forms are asexual stages and bear 



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