138 



The Classification of Lower Organis?ns 



Order Pyrcnomycetales Bessey in Univ. Nebraska Studies 7: 295 (1907). 

 Orders Hypocreales, Sphaeriales, and Dothideales Gaumann Vergl. Morph. 

 Pilze 222, 253, 284 (1926). 

 Ascomycetes producing, from a normal mycelium, perithecia, i. e., small fruits 

 of the shape of a small globe or flask opening through a single pore, the ostiole. 

 Sphaeria, which Persoon and Fries listed first under the names which they respec- 

 tively used, is the evident standard genus; but this genus has become broken up and 

 lost in the work of subsequent scholars. 



This order includes very many species and is by the generality of authority 

 divided into three. Forms whose perithecia are borne directly on the m.ycelium, 

 together with those whose perithecia are borne in or on but distinct from a dark 



Fig. 27. — Mycosphaerella personata after Higgins (1929), x 1,000; a, conidio- 

 phorcs and conidia of Ccrcospora type, b, longitudinal section of pycnidium; 

 C, primordium of perithccium with ascogonoium bearing a trichogyne; d, e, ascogen- 

 ous hyphae; f, crozier formation; g, longitudinal section of mature peridiecium. 



