ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 639 



Sclerotinia PirolaB.* — A. Grosse found in the capsules of PiroJa sp. 

 black sclerotia, of which he was able to trace the further development. 

 They are somewhat ovate in form and pointed at one end, and produce 

 1 to 4 fruiting bodies. Infection takes place from the beginning to the 

 middle of June. The sclerotium formed in the seed-capsule remains on 

 the plant during the season, and in the ground during a second year 

 before further growth ; it thus takes two years for normal development. 



Research on Fermentation Yeasts.f — R. Stoppel has made experi- 

 ments with different races of yeasts to test their comparative qualities 

 as fermentative agents. He found that the different kinds did not vary 

 to any extent in the amount of CO^ produced ; the loss in weight during 

 fermentation might vary as much between samples of the same culture 

 as between different races, but among the different yeasts some were 

 more sensitive to variations of temperature than others. The more 

 actively fermenting yeasts produced very little glycerin ; where less 

 alcohol was formed, there was more glycerin. The amount of acids 

 formed also varied. 



Study of Yea St. J — A. Sartory has made a biological study of a 

 yeast l)elonging to the genus Wiliia. It was isolated from tbe juice of 

 banana leaves, and was always accompanied by a bacterium. Results 

 are given as to growth on various media. Ascospores were formed when 

 the bacterium was added to the culture. The author recalls Molliard's 

 statement that tlie formation of apothecia was aided by the presence of 

 a bacterium. He suggests that this phenomenon may be of more fre- 

 quent occurrence than is generally supposed. The bacillus was cultivated, 

 and is also described. Neither organism is pathogenic. 



Study of Oospora (Oidium) lactis. § — Erwin Schnell finds th;it 

 there are a w'hole series of forms known as Oidium lactis, which haA'e 

 been more or less distinctly described. He has added another, Oidium 

 casei. All of them, at certain temperatures, after formation of mycelium, 

 break up into oidia, which remain in chains or fall asunder. All of 

 them form some acids, and break up others ; they change albumen into 

 free ammonia with odour of cheese, etc. On living fruits the different 

 forms, in certain conditions, not only destroyed albumens but pierced 

 the cell-walls, which they partly destroyed. Pressed yeast is killed by 

 the fungus, and then albumen changed to free ammonia, so that fer- 

 mentation is seriously hindered by the presence of Oidium. At the 

 same time, owing to its rapid growth, it forms a coating over pressed 

 yeast, milk, butter, cheese, etc., which protects them against infection 

 from the micro-organisms, and thus in certain conditions, Oidium is of 

 distinct service. It has been also found of service in cheese-making. 



Disease of Insects. || — W. P. Gee and A. P. Massey describe the 

 infection of the apple tent-caterpillar {Malacosoma americana) by the 



* Ann. Mycol. x. (1912) pp. 357-8. 



t Zeitschr. Bot., iv. (1912) pp. 625-39. 



t Ann. Mycol., x. (1912) pp. 400-4 (1 pi.). 



§ Centralbl. Bakt. xxxv. (1912) pp. 1-76 (6 pis.). 



11 Mycologia, iv. (1912) pp. 279-81 (1 fig.). 



