— 123 — 



and otliers explain the appearance of large nuclei in the ascogonia 

 in that луау. Notwithstanding the abundant material we had at 

 hand and the great quantity of respective stages which were wat- 

 ched, the absence in P. fimiseda of nuclei in pairs, that is so ta 

 say, nuclei ready to fuse, without speaking of the absence of fusing 

 nuclei, makes one doubt the correctness of such an interpretation 

 of this phenomenon and look for another explanation. 



At the investigations of other species of Podospora and Sordaria 

 special attention was given to this question, and these investiga- 

 tions Avere begun in the expectation that this new material would 

 be more successful in explainig this disputed and interesting que- 

 stion. The most suitable in this case seemed to be P. curvula and 

 S. fimicola. The first in consequence of its large nuclei, the second 

 in consequence of its extraordinarly rapid development. The fungus 

 matured, as already indicated, on the third or fourth day after 

 the infection of the nourishing medium. 



Podospora curvula. 



Podospora curvula, which was found in a wild state as often as 

 P. fimiseda, at the infection of the nourishing medium, gà\e simul- 

 taneously both conidial and asci fruiting. The conidia with one 

 nucleus develops in enormous quantities in short, swollen cells, 

 Avhich appear on the hyphae as side branches (fig. 17). One could 

 not succeed in germinating a conidia. As to the development of the 

 perithecium it does not in any way differ from that of the P. fimi- 

 seda. One notices the same absence of antheridia, the same spiral 

 coiled ascogonium, consisting of several cells, which form numerous, 

 ramifying ascogenous hyphae. Even the time of the appearance of 

 the ascogonia and the ripening of the fruit bodies is the same as 

 in P. fimiseda, that is on the fifth or sixth day the ascogonia be- 

 gin to form and on the 17 th. — 20 th. day the asci ripen. The 

 only difference is, that the sheath of the perithecium is to such an 

 extent transparent, that one can distinctly see the spiral of the 

 ascogonium, in somewhat late stages of development of the fruit- 

 bodies, without clearing and staining the section (fig. 18). 



The difference with P. fimiseda in the cytological sence is first 

 marked in the dimensions of the nuclei of the ascogonium and of 



