— 117 — 



The gathered material was fixed in situ with weak Flemming fiaid 

 and Merckel fluid (for Sordaria were used other fixers, see p. 130). 

 The best results were obtained (the use of the air pump being ne- 

 cessary) at the fixing of the fungus by the first of the two before 

 mentioned fixers, said the staining of the sections with Heidenhain's 

 iron haematoxylin. 



The germination of the spores, the formation of the ascogonia 

 and the early stages of development of the fruit-bodies were also 

 examined in a living state. When the sheath of the perithecium de- 

 veloped to such an extent, that its inner parts became ijiaccessible 

 for direct observation, great assistance was obtained by the wor- 

 king up of the section with 2^/^ KOH and slight staining with 

 Jiongoroth. Cleared and stained in this manner, the perithecium 

 was put into weakened glycerine, in which the cells, lying in the 

 -centre, stood out quite distinctly. 



For the investigation of living fungus were chiefly used cultures 

 grown on agar-agar. The first stages of development are easier 

 to trace in such transparent medium as agar-agar, than in 

 horse dung. 



For fixation the horse dung is preferable, as it is easy to take 

 off from horse dung small portions of mycelium with perithecia and 

 join together the fruit bodies, of the age needed for the investiga- 

 tion. Not to lose this material, by the inbedding into paraffine, it 

 лvas gathered in little piles on small pieces of paper (1 c/m. wide 

 ^nd iVo c/m. long). The papers were folded in two and carefully 

 pressed by leaden plates of equal size. The behydratining and clea- 

 ring was produced in them, and only just before the inbedding the 

 ■contents were removed from the papers into parafine. 



Podospora flmiseda. 



P. fimiseda can be considered as one of the forms, which is 

 oftenest obtained in a wild state. The germination of its ascospores 

 takes place, as stated by Woronin, in the following manner: the 

 outer sheath, of the spore swollen in the fluid, splits always at 

 the top, and the inner colorless sheath comes out, and looks like 

 a globular swelling. This globular cell is filled with a dense sub- 

 :stance. It gives from two to three side branches, which grow to 



