FIMETARIACEAE (SORDARIACEAE) 



201 



of a plus strain or class and a minus strain or class, for each strain 

 produces both male and female organs and is thus bisexual or 

 hermaphroditic. Obviously the difference between strains must 

 be based on compatibility. 



A 



^. 



D 



^ 



■1 



B 



Fig. 74. Pleurage anserina. A. Peritherium in silhouette. B. Tip of 

 trichogyne with spermatium attached. C. Mature ascus containing three 

 normal and two dwarf spores. D. Ascogonium before fertilization. E. 



Clusters of spermatia. (After Ames.) 



In Pleurage zygospora, which has 16 spores, Lewis (1911) 

 found that the typical 8 free nuclei are formed; each then be- 

 comes delimited by a membrane. Additional nuclear divisions 

 to form a sporogenous filament follow. A functional spore is 

 cut off from each end of each filament, thus making 16 asco- 

 spores. In Philocopra {Sporonnia) coeriileotecta [Jolivette-Sax 

 (1918)], on the other hand, free nuclear divisions occur until 128 

 nuclei are formed, whereupon the ascospore membranes are 

 developed. 



