266 



CLASS ASCOMYCETEAE 



Fig. 88. Pseudosphaeriales, Family Pleosporaceae. Venturia inaequalis (Cke.) 

 Wint. Stages in sexual reproduction. (A) The forked antherid is in contact with the 

 exserted trichogyne. (B) The sperm nuclei are passing from the antherid (above) into 

 the trichogyne. (C) The ascogonial cells have become multinucleate and are beginning 

 to form lobes; the cross walls of the trichogyne have dissolved. (After Killian: Z. 

 Botan., 9:353-398.) 



gyne, as described by Killian (1917) and by Frey (1924). In Fimetaria 

 {Sordaria) fimicola (Rob.) Griffiths and Seaver it was shown by Greis 

 (1936) that the tip of a slender antherid fuses with the apex of a coiled 

 ascogonium. The antherid may arise from adjacent cells or from separate 

 hyphae. In the lack of an antherid any cell of the ascogonium may send 

 out an extension, a "pseudotrichogyne," to some nearby cell from which 

 a nucleus is obtained. This species is self -fertile, i.e., there are not two 

 sexual phases as in Schizothecium anserinum. Elliott (1925) reported that 



