260 



COMPARATIVE MORPHOLOGY OF FUNGI 



While the Chaetomieae in Chaetomidium probably show the root of the 

 family, the Sordarieae (Griffiths, 1901; Griffiths and Seaver, 1910) in 

 Sporormiella and in some species of Sordaria (subgenus Hypocopra) 

 in which the perithecia (as in the higher Melanospora species of the 

 Hypocreales) are embedded in the stromata and extend in the direction 

 of the stromatic Pyrenomycetes. The Sordarieae also are richer in 



Fig. 174. — Philocopra coeruleotecta. Development of ascospores. 1. Young ascus 

 with primary nucleus. 2. Elongated ascus. 3. First division of primary nucleus. 4. 

 Ascus with young spores. 5. Section of young ascus. 6. Swelling of upper end of asco- 

 spores. 7, 8. Older stage. 9. Mature ascospores with stipe cell. (1, 4 to 7, 9 X 800; 

 2, 3, 8 X 920; after J olivette-Sax, 1918.) 



forms than the Chaetomieae and thus show more peculiar relationships, 

 especially in the structure of their ascospores. In Sordaria (Fimetaria) 

 and in Podospora, Philocopra (Pleurage) the ascospores are usually unicellu- 

 lar, in the former provided with a hyaline gelatinous sheath, in the latter 

 with two or more gelatinous appendages. In many species they subse- 

 quently undergo a further development ; in Philocopra caeruleotecta, there 

 are first laid down 128 thin- walled spherical ascospores which elongate 

 (Fig. 174, 1 to 6). The nucleus of each migrates to the upper end which 



