ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 337 



In a further paper * in the same journal, Hansen discusses the con- 

 ditions necessary or favour-able to the vegetative and spore-development 

 of yeasts and of the moulds that take part in alcoholic fermentation. 

 He finds that oxygen is necessary for spore-formation in yeast, though 

 the ordinary yeast-growth can go on in an atmosphere of nitrogen, free 

 from oxygen. Nourishment is not so important as a determining factor : 

 spore-formation as well as budding takes place in rich cultures. Ex- 

 periments were also carried out on several species of Mucor, and the 

 conditions given by which zygospores or sporangia can be produced. 

 There are four illustrations. 



Development of Yeast in Sugar Solution without Fermentation .] 

 Iwanowski publishes a reply to A. Richter, and repeats his work on 

 yeast. He finds that the two most important factors in inducing 

 fermentation are the concentration and the composition of the culture 

 solution. The higher the ratio of nitrogenous substance the weaker the 

 fermentation, which again becomes stronger with a larger amount of 

 sugar. He gives detailed tables of his experiments and the results 

 obtained. In two succeeding numbers of the journal he continues the 

 discussion, repeating his experiments. He gives careful tables of the 

 composition, duration, and temperature of his cultures, and affirms again 

 that yeasts can live on sugar almost without alcoholic fermentation in 

 suitable conditions. That is, in a solution of weak concentration. He 

 also proves that the presence of oxygen exerts considerable influence on 

 the results obtained. 



Industrial Ferments of Eastern Asia.J — H. Xeuville has published 

 an account of the various organisms employed by the Chinese and others 

 in making spirits from rice, &c. A number of forms of Mucor used in 

 fermentation are described, as also species of Aspergillus, Monilia, and 

 Saccharomyces. The last chapter of the book deals with the substances 

 employed in fermentation. 



Asterconium Saccardoi.§ — H.and P. Sydow found this new member 

 of the Melanconise on leaves of Litsea glaucescens from Mexico. Both 

 sides of the leaf bore the cushion-like outgrowths that contained the 

 spores, which are colourless, one-celled, and with conical protuberances 

 that give them a star-like form. 



Septoria.|| — M. C. Potter describes the disease of carnations due to 

 Septoria Dianthi. The affected parts are of a light straw colour, the 

 tissues shrink, and the leaf often curls longitudinally. On the diseased 

 areas there are small black pycnidia filled with the long colourless 

 spores of the Septoria. The disease was first noticed by the writer in 

 Warwickshire. 



An account IT of a severe epidemic caused by the same parasite in 

 Liguria and Provence is given by P. Voglino. He finds that the fungus 



* Tom. cit. See also Centralbl. Bakt., torn, cit., pp. 125-30. 



t Centralbl. Bakt., x. (1903) pp. 151-4, 180-3, and 209-14. 



% ' Encvclope'die scientifique des aide-memoires,' Paris, 1902, 192 pp. See also 

 Centralbl. Bakt., x. (1903) pp. 130-1. 



§ Ann. Myc, i. (1903) pp. 35-6. 



|| Journ. Boy. Hort. Soc, xxvii. (1903) pp. 428-30 (3 figs, in text). 



f Stazioni Sperimentali Agrarie, xxxv. (1902) p. 17 (3 rigs.). See also Centralbl. 

 Bakt., x. (1903) pp. 108-9. 



