456 SUMMARY OF CURRENT RESEARCHES RELATING TO 



third Ascomvcete, EJmtheromyces hngisporus, was found on the Plasmo- 

 dium of a Myxomjcete. As the spores are septate, he founds for it a 

 new genus Eleutheros})ora, of which a diagnosis is given. 



Eremascus fertilis sp. n.* — Rose Stoppel found this new fungus 

 growing in great abundance in some jars of fruit jelly which had not 

 been opened for four years. Cultures were tried and were easily success- 

 ful, and observations were made both on living and on fixed material. 

 The author found the beginnings of asci on the fifth day after sowing 

 the spores ; there were small outgrowths from the neighbouring cells of 

 the hyphffi which wound round each other, the wall between breaking 

 down at the apes and conjugation of the two cells taking place. The 

 joint cell is the young ascus in which from 4-8 spores are formed. 

 If more spores were developed none of them ripened properly. As 

 to more definite cytological work, the author found that the number 

 of nuclei in the cells of the mycelium was variable — 1, 2, or more, up to 

 15. It was noted that immediately after germination the germinating 

 tube contained 6-S nuclei. One nucleus was distinguished at the base 

 of each of the ascus-forming outgrowths, which passed into the fused 

 cell ; in the young ascus one nucleus alone appears, but always with 2 

 nucleoli, and it is much larger than the original nuclei. Evidence was 

 forthcoming that mitotic divisions succeeded, but the nuclei were too 

 minute to allow of detailed observations. The divided nuclei always 

 lay over each other. 



In many other Ascomycetes a double fusion of nuclei has been proved : 

 the first fusion in the aseogonium, the second in the young ascus, but the 

 author considers the two copulating hyphaj in Eremascus fertilis to be 

 equivalent to aseogonium and antheridium such as are found in Phyl- 

 hidiniu, and that the nuclear fusion is a sexual act. She discusses the 

 bearing of these phenomena on the systematic position of the fungus, 

 and leaves it close to Gymnoascus, although the latter is a much more 

 complicated form. 



History of the Development of Ascomycetes.t — P. Claussen has 

 reviewed the papers that have been pul^lished on the sexuality of the 

 Ascomycetes in recent years, and gives a history of the progress of our 

 knowledge of that particular branch of cytology. He agrees entirely 

 with those writers who hold as proved the existence of sexuality in many 

 of the forms, and cites at length the different works in which the 

 subject is described and discussed. He also goes into the question of 

 the development of the ascus, and the significance of the nuclear fusion 

 that always takes place in the young ascus. He does not consider it to 

 be sexual fusion, as that would imply a second sexual fusion, which is 

 not probable. The paper is illustrated by figures in the text, and 

 further enriched by an exhaustive bibliography of the subject. 



Origin of Yeasts. | — A Guilliermond takes up the discovery by 

 Yiala and Pacottet of so-called asci in a yeast formed from an asco- 

 mycetous fungus, and reviews the whole question. He gives a history 



* Flora, xcvii. (1907) pp. 332-45 (2 pis. and 6 figs.). 



t Ber. Deutsch. Bot. GeselL, xxiv. (1907) pp. 11-38 (7 figs.). 



X Ann. Mycol., v. (1907) pp. 49-69 (23 figs.). 



