SPHAERIALES 



157 



long hairs around the ostiole, and from the Sphaeriaceae in the habitat and 

 type of spore. The mycelium is in most cases composed of multinucleate 

 cells, but in Podospora hirsuta the .cells are uninucleate (fig. 115), recalling 

 the condition in several species of Chaetomium. 



The commonest type of archicarp is a stout, coiled, septate hypha which 

 soon becomes surrounded by vegetative filaments; it is usually terminal, but 

 is occasionally intercalary, for instance in Sordaria fimicola. Dangeard has 

 found a straight archicarp (fig. 1 16) in Sordaria macrospora, and in 1868, for 

 S. fimiseda, Woronin described an archicarp with a swollen terminal cell 

 recalling the oogonium of Humaria grannlata. 



Fig. if 5. Podospora hirsnta 

 Dang., archicarp; alter Dan- Fig. 116. Sordaria macrosforaAuersw.; a. straight archicarp; after 

 geard. Dangeard. 



In Sporormia intermedia the perithecium is initiated by the enlargement 

 of a multinucleate mycelial cell which is often intercalary. It undergoes 

 not only transverse but also longitudinal divisions, forming a pseudoparen- 

 chymatous massof uninucleate cells(fig. 1 17), with which various neighbouring 

 cells anastomose. The mass thus formed is responsible for the whole contents 

 of the perithecium, though the outer walls may be formed by ordinary 

 vegetative hyphae. In view of this fact it seems doubtful whether the initial 

 cell should here be regarded as an 

 oogonium, that is to say as having at 

 one time had a sexual significance, 

 and not rather as a preliminary stage 

 in the development of such a mass of 

 hyphae as initiates the apogamous 

 perithecium of Claviceps and its allies. 



\L 



In some of the Sordariaceae each 

 spore is surrounded by a layer of 



Fig. 



117. Sporormia intermedia Auersw. ; initial 

 cells of perithecium ; after Dangeard. 



