MYCOSPHAERELLACEAE 



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Fig. 80. Mycosphaerella jraxinicola. A. Mature spermogonium, in section, 

 of "multilocular" appearance. This appearance may be accounted for be- 

 cause, in spermatial formation, all chains of spermatiferous cells do not bear 

 spermatia at the same time. B. Spermatium mother-cell whose content is 

 quadrinucleate. Spermatia are abstricted as the mother-cell contents migrate 

 into the sterigma seriatim. C. Multicellular ascogonium. D. Uninucleate 

 nurse cells from the interior of the young perithecial locule. E. Mature 

 ascus. F. Young perithecial locule containing three ascogonia. Both 

 spermogonial and ascogonial locules develop coincidentally. 



