SPHAERIALES 



261 



swells clavately, thickens, browns its wall and is ab jointed from the 

 enucleate hyaline lower part (Fig. 174, 7 to 9) (Jolivette-Sax, 1918). 

 In Philocopra zygospora, they elongate to many times their original length 

 and undergo several nuclear divisions, whereby in time they generally 

 lay down several septa (Lewis, 1911). The two end cells (always 

 uninucleate) swell strongly, thicken their wall, form echinulate 

 appendages and develop to true spores (Fig. 175, 5), while the intermedi- 

 ate part gradually dissolves. Functionally, 16 ascospores are formed, 

 morphologically, only 8. 



It is possible that these two types were originally from scoleco- 

 sporous ancestry and that we have in them a special differentiation of 



Fig. 175. — Philocopra zygospora. Development of ascospores. 1. Young ascus with 

 diploid nucleus. 2. Ascus with eight young ascospores. 3. The ascospores have devel- 

 oped to septate filaments. 4. Showing the swelling ends of the ascospores. 5. Mature, 

 three-celled ascospore. (X 590; after Lewis, 1911.) 



Epichloe-like, septate spore chains. Unfortunately, too few repre- 

 sentatives of this type have been investigated cytologically; a beginning 

 or end member of this developmental series is possibly Podospora anserina 

 whose ascospores are said to be always binucleate (Wolf, 1912). In 

 other genera, the ascospores remain multicellular, as bicellular in 

 Delitschia, quadri-multicellular in Sporormia. Imperfect forms are rarer 

 in the Sordarieae. In cultures Podospora Brassicae, on short branches, 

 cuts off hyaline conidia which unite into large heads ; Sporormia megalospora 

 forms pycnia with bacilliform, hyaline conidia (Brefeld, 1891). 



While in the Sordariaceae, the perithecia are generally fleshy to 

 membranous and hence appear like the simpler Hypocreales, as species 

 of Melanospora, in the following families they are formed as in true 



