ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 73 



the product of the stigma, increased somewhat by the excitation of the 

 attack of the fungus. 



R. Aderhold * has been working at the same subject, studying the 

 conditions of the development of the fungi from the sclerotium. They 

 grow most readily under a very slight coating of earth. Deeply buried 

 sclerotia were never seen to germinate, but they could persist in that 

 condition unimpaired in vitality till the following year — after that the 

 power of growth had gone. - 



Conjugation of Yeast-Spores.t — A. Guilliermond again takes up the 

 question of fusion in the spores of certain species of Saccharomyces. He 

 describes the method employed in growing, fixing, and staining the 

 yeasts, and gives an account of the results observed for each form. He 

 devoted special study to S. Ludwigii. The ascus of this species contains 

 four spores, which constantly unite in pairs in the interior of the asqus. 

 A germinating tube is then formed, which pierces the ascus wall and cuts 

 off a succession of cells like the budding of other species. In other 

 cases the spores each form a germinating tube, and fusion may take 

 place later between two tubes, or there may be no fusion at all. Guil- 

 liermond then describes the fusion of the nuclei. There is a slightly 

 different procedure in S. Johannisberg ii. More than half the number of 

 spores conjugate at the time of germination, but fusion is not so con- 

 stant between spores of the same ascus. In the Schizosaccharomycetes 

 and the Zygosaccharomycetes, fusion as a rule takes place between two 

 cells at the formation of the ascus. In some forms there are often cases 

 where no fusion takes place, showing a tendency to apogamy. Many 

 deviations from the usual development are noted by the author, and 

 comparison is drawn between these cases of fusion in yeasts and the 

 sexual fusion noted in the Ascomycetes. He has no doubt that these 

 fusions are veritable conjugations, though the sexuality is of a somewhat 

 rudimentary character. 



Occurrence of Saccharomyces anomalus in the Brewing of Sake.J 

 K. Saito found this yeast constantly in specimens of sake from numerous 

 localities. He grew it in various cultures, and describes at length its 

 appearance and habits of growth. The formation of endogenous spores 

 was easily induced ; they are cap-shaped, and are 2-4 in a cell. Saito 

 tested the effect of carbohydrates in the cultures and also the products 

 of fermentation. In all of these, the sake yeasts resembled Saccharo- 

 myces anomalus. The writer is not sure of the part played by the yeast 

 in the preparation of sake, but he thinks that the aroma is very probably 

 due to its presence. 



Conidial Form of Aspergillus niger.§ — C. Engelke describes an 

 alternative form of the fungus hitherto known as Sceptromyces opizi, or 

 Botrytis sceptrum. The development of this second form is induced by 

 low temperature, moisture, and lack of nitrogen in the substratum. 



* Arb. Biol. Abt. Land. Forstw. k. Ges. Anit., v. (1905) p. 31. See also Ann. 

 Mycol., iii. (1905) pp. 378-9. 



t Rev. Gen. Bot., xvii. (1905) pp. 337-76 (4 pis. and 11 figs.). 



% Zeitsch. Angew. Mikrosk. Klin. Chemie, xi. heft 5 (1905) pp. 119-29. 



§ Jahresb. Nat. Ges. Hann., 1905, pp. 107-9. See also Ann. Mycol., iii.^(1905) 

 p. 373. 



