FUNGI IMPERFECTI 



615 



different groups and named differently according to the stage of develop- 

 ment. We have observed this earlier in the synonymy of the pathogenic 

 Ascomycetes. 



There is also the difficulty that all forms of conidial fructifications 

 do not permit of arrangement in Saccardo's scheme {e.g., Leucophlebs, 

 Zeller and C. W. Dodge, 1924). Therefore there has been an attempt to 

 enlarge the system or to replace it by a different one. Thus Potebnia 



A B 



Fig. 404. — Pestalotia versicolor. A. Conidia on branched hypha. B. Young stromatic 

 layer formed in a solution. (After Leiniger, 1911.) 



(1909) attempts to classify these fungi into five instead of three, groups: 

 the Hyphales, in which the conidial hyphae are free; the Coremiales, in 

 which they are united into coremia; the Acervulales, in which the conidia 

 are borne on the upper surface of stromata; the Pseudopycnidiales, in 

 which the conidia are borne in pseudopycnia, which either, as in the 

 perithecia of the Plectascales, rupture irregularly or by narrow slits 

 (Leptostromataceae type) or, as in the apothecia of the Discomycetes, 

 become patelliform at maturity (Excipulaceae type) ; and into the Pycni- 

 diales, in which the conidia are enclosed in true pycnia. 



