ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 457 



of work done on yeasts, and insists on the difference supposed to exist 

 between Saccliaromyces and the yeasts of the higher fungi, that the 

 former produces eudospores while the others do not. He recalls also the 

 work done by Harper and Dangeard on the cytology of the ascus, and 

 contrasts Saccharomyces with Endomyces and Dipodascus. He allows 

 that Viala and Pacottet have made exact observations, but he comes to 

 the conclusion that in their cultures there must have been two fungi, a 

 Gloaosporium and a yeast, living symbiotically together, and extremely 

 difficult to separate. 



Grlycogen in Yeast-cells.* — F. G. Kohl considers that glycogen 

 regulates and conditions the absorption of sugar in yeast-cells. The time 

 of most active cell-multiplication and fermentation is the time when 

 glycogen is most abundant. Resting yeast was tested, and the substance 

 was found to be present only in small quantities. The author scarcely 

 looks on it as a reserve product, and he doubts if it functions as such in 

 other fungi ; thus it is not found in resting sclerotia, but only when the 

 germination begins. Kohl gives an account of the staining and exami- 

 nation at various stages of the yeast-cells with reference to their glycogen 

 content, and to the changes that take place during sporulation. Though 

 this substance was abundant in the budding cells, it was not found in 

 the spores, so long as they were still within the mother-cell. 



Mycological Studies.! — A. Potebnia, from Charkow in Russia, has 

 made a special study of the Sphjeropsidete, and has examined _ and 

 experimented with 24 different species. He has demonstrated the circu- 

 lation of protoplasm in the cells, as also the connection of one cell with 

 another by pits in the walls which become almost closed up as in older 

 hyphge. The observations made on this phenomenon, both in immersed 

 and in aerial hyphge, are carefully described. Notes are given on the 

 ejection of plasma from the cells. He considers it an abnormal occur- 

 rence, and that the plasma loses vitality. External influences, tempera- 

 ture, moisture, etc., induce or hinder this ejection. 



Considerable attention has been paid by Potebnia to the systematic 

 arrangement of the Sphferopsidefe : imperfect descriptions and immature 

 specimens are responsible for a good deal of confusion. Then similar 

 morphological members of the Sphsropsidefe have their perfect form in 

 widely diversified Ascomycetes. He has grown these pycnidial forms on 

 artificial media, and he notes the recurring characters that would be 

 lielpful in diagnosing and in proving relationship in the groups. He 

 hopes by further study to advance our knowledge of the Deuteromycetes. 



Potebnia also gives a list of fungi collected in Gowv. Kursk and 

 Charkow, a few of them being new species ; a bibliography of works 

 bearing on the subject discussed, and an index of host-plants with the 

 fungi which he has found growing on them, are added to the paper. 

 The hst includes 181 species of fungi, 



Ascogenous Forms of Grlceosporium and Colletotrichum.J — C. L. 

 .Shear and Anna K. Word have added to our knowledge of the life- 



* Ber. Deutsch. Bot. Gesell., xxv. (1907) pp. 74-85 (2 figs., 1 pi.). 

 t Ann. MycoL, v. (1907) pp. 1-28 (3 pis.). 

 X Bot. Gazette, xliii. (1907) pp. 259-66. 



Aug. 21st, 1907 2 H 



