THE FUNGI WHICH CAUSE PLANT DISEASE 



271 



cylindric to broadly clavate, blunt, 45-55 x 9-10 n; spores 

 curved, continuous, granular, 13-15 x 5-6 /i. 



Conidia (=Glceosporium psidii), acervuli subepidermal on defi- 

 nite spots, 90-120 ju; conidiophores hyaline, cylindric, 15-18 x 

 4-5 ju; conidia elliptic, oval, hyaline, 10-13 x 4-6 /t. 



Artificial culture studies by Sheldon ^*'' ^* demonstrated the 

 ascigerous stage. Extensive study was made of the growth on 



FiQ. 200. — G. piperata, 99, perithecium external and in sec- 

 tion. 100, asci in detail. After Stoneman. 



apple-agar, apples, plums, etc. Two distinct forms of conidia 

 were observed, one on loose hyphse, the other in acervuli. The 

 species should probably be regarded as a variety of G. rufo- 

 maculans. 



It occurs on the guave. 



G. gossypii (South.) Edg. 



Perithecia distinct or crowded, very abundant, covered, dark 

 brown to black, subglobose to pyriform, 80-120 x 100-160 m, 

 beak up to 60 /t long; asci numerous, clavate, 55-70 x 10-14 n; 



