ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 473 



cell contents. If a trace of yeast cells from a culture is placed in distilled 

 water with a definite mixture of mineral and sugar solution, the mineral 

 is taken up by the protoplasm of the cell and death follows ; but if a 

 large quantity of yeast is placed in the same mixture no harm is done. 



Heinrich Zikes* describes a new species of " anomalous " yeast, Will/a 

 Wichmcmm. It has the peculiar cap form of the other members of this 

 group. The author describes the characters of the group, and then 

 gives the history of the new species which was isolated from the soil in 

 the neighbourhood of Vienna. 



Nuclear Division in Yeast.f — Franz Fuhrman has made a cyto- 

 logical study of Saccharomyces elli/psoideus I. Hansen. He compares his 

 results with those recently published by Schwellengrebel, and finds that 

 though they agree in the main there are some small differences to be 

 noted. He finds that division results in two equal daughter-nuclei ; 

 Schwellenberg had noted a difference in size and that the smaller nucleus 

 migrated to the newly formed cell. He sums up the phases of karyo- 

 kinesis thus : — 



1. Formation of knot stage, increase of chromatic substance, and 

 disappearance of nuclear membrane. 



2. Formation of apparently four chromosomes. 



3. Arrangement of chromosomes in monaster, and formation of 

 achromatic spindle (perhaps with centrosomes). 



4. Division of chromosomes into daughter-chromosomes. 



5. Formation of diasters. 



6. Polar deposition of chromosomes, resembling the knot stage. 



7. Return of each daughter- nucleus to the resting condition. 



The writer never detected any case of nuclear fusion in his prepara- 

 tions. As to the budding stage, in general, it begins at a later period 

 than nuclear division. In most cases it began with the monaster stage, 

 but it sometimes took place earlier. He found it very rarely occurring 

 at the same time as the diaster stage. Migration of the nucleus occurred 

 most frequently at the knot stage, after which a resting period ensued. 



Symbiotic Yeast. J — L. Lutz published in the Bull. Soc. Mycol. 

 France, 1809, p. 68, an account of "Tibi," a symbiotic growth of a 

 yeast and bacillus that is used in Mexico, along with sugar, to form a 

 fermented liquor. The yeast is named Saccharomyces Radaisii, the 

 bacillus is B. mexicanus. His object has been to attempt the associa- 

 tion with other bacilli, but he was only successful with B. subtiUs, The 

 two organisms formed the small creamy balls which produced the 

 fermentation. The association in the case of other bacilli was not 

 stable, and one symbiont gradually displaced the other. The function 

 of the bacilli is to form an anaerobic environment for the yeast. 



A New Lichen Parasite. § — A. Zahlbriickner found that the fruit 

 of the lichen Caloplaca callopisma was deformed by the presence of a 

 fungus which grows on the hymenium. From the hypha? of the fungus 



* Centralbl. Bakt., xvi. (1906) pp. 97-111. 



+ Op. cit., xv. (1906) pp. 769-77 (1 pi.). 



+ Bull. Soc. Mvcol. France, xxii. (1906) pp. 96-8. 



§ Ber. Deutsch. Bot. Gesell., xxiv. (1906) pp. 141-6 (1 pi.). 



Aug.' loth, 1906 2 I 



