392 SUMMARY OF CURRENT RESEARCHES RELATING TO 



to the acidity or alkalinity of the substratum. Marc Medisch has 

 therefore conducted a scries of culture experiments to obtain physio- 

 logical ilata concerning the growth of fungi. In a solution of weak 

 glycose the solution itself became intensely yellow, owing to oxidation 

 which the addition of various salts to the solution tended to accelerate. 

 The colour could again be destroyed by reducing substances ; reducing 

 bacteria, however, had only a slight effect on the colour. An addition 

 of nitrogen compounds had also a more or less strong influence on the 

 coloration. Further details are given of the influence of ammonia 

 salts, nitrates, and nitrites. 



North American Fungi.* — F. J. Seaver contributes an account of 

 the Nectriacese and Hypocreacese. He has drawn up synoptic tables of 

 the genera, and in some cases of the species also. He has resuscitated 

 some old genera such as Typhodium (Epichloe) and Spermoedia (Claviceps). 

 Helen Letitia Palliser deals with Chsetoruiaceaa, and D. Griffiths, along 

 with F. J. Seaver, describe Fimetariaceae, a new family to take the place 

 of Sordariacese, with a new genus Fimetaria instead of Sordaria. 

 Another old genus, Plenrage Fries, is also re-employed for species of 

 Podospora, etc. 



Mildew of Gooseberry and Oak.| — Gustav Kock reports that the 

 American gooseberry mildew appeared, in Galicia in August 1906, and 

 that an appeal was at once made that all cases of the outbreak in 

 Austria should be notified. It was again observed in 1907, and spread 

 further the following years. The oak mildew appeared in 1907 on 

 Quercus pedunculate, especially on scrub-oak. The steady and rapid 

 progress of the disease is described by the author. 



Copulation of Yeast-cells. $ — A. Guilliermond has already published 

 his observations on Debaryomyces ylobosus, in which he had noted fusion 

 of two isogamic cells before ascus formation. At the same time it was 

 noted that the ascus was frequently formed without such fusion .- so that 

 parthenogenesis is a frequent phenomenon, and copulation is not indis- 

 pensable. Guilliermond has continued the research on various forms, 

 and he finds a retrogression towards parthenogenesis, comparable to that 

 of Saprolegnise, as pointed out by De Bary. 



Presence of Yeast on Tea.§ — The fermentation of tea is due to a 

 process of oxidation. Ch. Bernard thinks that possibly yeast-cells may 

 play a part in the development of the aroma. He has found yeast-cells 

 constantly present on tea-leaves, and they increase abundantly during 

 the stages of tea-collecting, etc. It seems to be constant in the different 

 plantations, and certainly is not deleterious. The presence of bacteria 

 is disadvantageous, as they give a bad odour and make the tea viscous. 



Cicinnobolus sp. parasitic on Sphgerotheca mors-uvse.|| — Otto 

 Oberstein-Breslau records the appearance of the American gooseberry 

 mildew at Schonfeld. He also found the mildew parasite, Cicinnobolus, 



* North American Flora, iii., 1 (1910) 88 pp. 

 t Zeitschr. Pflanzenkr., xx. (1910) pp. 452-5. 

 t Comptes Rendus, clii. (1911) pp. 448-50. 



§ Bull. Dept. Agric. Ind. Neerl., No. 36 (1910). See also Bot. CentralbL, cxiv. 

 (1910) p. 617. || Zeitschr. Pflanzenkr., xx. (1910) pp. 449-52. 



