34-4 SUMMARY OF CURRENT RESEARCHES RELATING TO 



publishing their atlas of 17 plates, each containing six micro-photographs 

 of yeasts, and representing o2 different species. The plates appeared 

 originally in the "" Brewing Trade Review," and have now been issued 

 in atlas form, each plate being accompanied by a short explanatory note. 

 The authors restrict the term Saccharomycetes to those budding fungi 

 which are capable of reproducing by the formation of ascospores. Some 

 of these are much cultivated for industrial use, others more or less 

 associated with them are " technologically pathogenetic," and are capable 

 of communicating to the products of their fermentative activity flavours 

 and odours, or other undesirable characters. 



The industrial culture yeasts are treated first in order, and the 

 different plates show various growths and developments — sedimentary 

 forms, budding forms, young films, formation of ascospores, etc. The 

 magnification is the same in most cases, so that comparison is rendered 

 simple and easy. Incidentally explanations are given of such terms as 

 " Saaz," " Frohberg," and " Logos," which refer to the breweries where 

 the yeasts have originated. On the fifth and succeeding plates photo- 

 graphs are reproduced of wild yeasts and some other forms. These 

 yeasts occur in nature, some of them growing on the outside of various 

 fruits, and give certiiin desirable qualities (or the reverse) to wine, beer, 

 ■etc. A few have been isolated from the air of the brewing houses, 

 among these being S. ■pastnriamis /., a virulent *' disease " yeast which 

 imparts an intense and nauseous bitter flavour to beer. Other yeasts are 

 represented which have been found in certain slimy secretions of oak 

 trees, and on the damaged roots of an elm tree. Finally, three photo- 

 graphs are given of Zygo-saccJtaromyces, discovered by Barker on com- 

 mercial ginger. The unusual phenomenon of conjugation is found to 

 occur in this fungus : the cells put out small protulierances, and where 

 two of these happen to be in proximity to each other, they unite, 

 becoming connected by a narrow canal. The photographs are remark- 

 ably clear, and show the characteristics of the various species under 

 different conditions of culture. 



American Fungi.* — Two parts of the " North American Flora," 

 dealing with the fungi of the country, have just been issued. J. C. 

 Arthur edits the Uredinales, which have been arranged according to 

 his own conception of systematic order in that group, with all the 

 new genera proposed by himself. G. P. Clinton has taken charge of 

 Ustilaginales, comprising Ustilaginaceag, with eleven genera represented in 

 the States, and Tilletiacete, with seven genera. Clinton's part is com- 

 plete, and is provided with a good host-index. 



Uredinese.f — E.Fischer reviews the recent literature bearing on 

 heteroecy and specialisation in the Uredinefe. He notes the increasing 

 number of forms that have been proved to be heteroecious. Much of 

 the work in the field has been done by J. C. Arthur in North America, 

 while Tranzschel. W. Miiller, W. Kreig, and Semadeni, have conducted 

 experiments with varying results in the Old World. The existence of 

 specialisation in this group has also been proved. Lately P. Cruchet 



* North American Flora, vii. (1907) part 1 (Ustilaginales) 82 pp. ; part 2 

 {Uredinales) 160 pp. + Bet. Zeit., Ixv. (1907) pp. 49-54. 



