PYRENOMYCETES 



287 



through the stomata into the air, after the manner of 

 Ramularia and other leaf parasites. 



The mycelium is white and forms a delicate white felt 



FIG. 71. Microsphaeria grossulariae, a 

 parasite on the gooseberry plant, i, gooseberry 

 leaf with white patches of the conidial form of 

 the fungus: the minute black points are peri- 

 thecia; 2, a perithecium with its appendages; 

 3, the branched tip of an appendage ; 4, 5, asci 

 containing spores. Fig. i, nat. size ; the re- 

 mainder highly mag. 



on living leaves, young shoots, and fruit, and is popularly 

 known as mildew. The conidia are one-celled, more or 

 less cylindrical, and most frequently produced in chains at 

 the tips of slender, erect conidiophores, which are simple 



