620 SUMMARY OF CURRENT RESEARCHES RELATING TO 



yeast and of the ascospores. The latter are cap-shaped, and are 2-4 in 

 a cell. He considers the yeast to be closely related to Saccharomyces 

 anomalus. 



The Yeasts of Charente.* — Andre Descoffre divides his work on 

 yeast into six chapters, which treat of (1) the origin of yeasts and their 

 dissemination ; (2) the technical microbiology adopted for the selection 

 of species and races ; (3) anatomical and physiological researches ; (4) 

 the action of exterior agents of different kinds on these micro-organisms ; 

 (5) the fermentation of the " must " of GharenU ; (6) resume and 

 conclusion. He takes note of the discoveries already made as to the 

 hibernation of yeasts in the soil ; some live on the surface, others 

 pullulate at a depth of 10 cm. Insects play a considerable part in dis- 

 semination, but the wind is the chief agent. The quality of the yeast 

 is strongly affected by the soil, the special Charente growth being limited 

 to the chalk soils. Definite odours and flavours are given to the product 

 of fermentation according to the species of yeast employed. The author 

 gives instructions how to secure the desired results. He also describes 

 methods of examining, staining, etc., the yeast cells. Spores are formed 

 in three days in Saccharomyces ellipsoideus campaniensis when the fungus 

 is grown on porcelain. 



Development of Yeast in the Soil.f — Emil. Chr. Hansen published 

 a paper on this subject some time ago. He found then that, in nature, 

 yeasts grew largely on decaying fruit and, in moist situations, on plant 

 remains, etc. But he found then, and has again proved, that the soil 

 is the great breeding ground not only in winter but during the whole 

 year. His researches included Saccharomyces and species of Torula and 

 Mucor. He remarks on the great power of resistance to drought possessed 

 by Mucor. 



Research on Fungi imperfecti.l — H. Klebahn has attacked the 

 problem of the pycnidial form of the Pyrenomycetes, and in two cases 

 he has established the connection between the different life-stages of 

 growth. The first he experimented with was Phleospora Ulmi, a para- 

 site of the leaves of different species of elms. It forms a hymenial 

 layer of hyphae under the lower surface of the leaf, and from the 

 hymenium are given off colourless, 3-septate spores. Phleospora has 

 been reckoned among the Sphgeroidege, but there is no perithecial 

 chamber formed, and the habit of growth accords more nearly with the 

 Melanconiese. Klebahn successfully infected young leaves with the 

 spores from Phleospora, and reproduced the pycnidial form. By keeping 

 infected" leaves in suitable conditions during the winter, he got the asco- 

 sporous stage, My co splicer ella Ulmi, a small perithecium imbedded in the 

 decaying tissue of the leaf. The ascospores were sown on the young 

 leaves, and they gave rise to Phleospora Ulmi. 



* Bordeaux (1904) i., 8vo, 128 pp. See also Bot. Centralbl., xcviii. (1905) pp. 651-2. 



t Centralbl. Bakt, xiv. (1905) pp. 545-50. 



t Jahrb. Wis8. Bot., xli. (1905) pp. 485-560 (75 figs.). 



