698 SUMMARY OF CURRENT RESEARCHES RELATING TO 



He finds such an ancestor in Sporodinia, where the resting spore, the 

 zygote, is formed by the fusion of primitive coenogametes with numerous 

 nuclei, and where azygospores are frequent. He looks on the conidium 

 of Empusa as a sporangium into which has been extended the ccenocytic 

 habit. Apogamy has become constant in Empusa, resulting in the 

 formation of multinucleate azygospores, as in Sporodinia. Thus from 

 Sporodinia he traces the development of Empusa, Entomophthora, and 

 Basidiobolus, indicating in each genus the points that establish his 

 theory of descent. 



Fungus Flora of Luxemburg.*— Joh. Feltgen published a pre- 

 liminary account of the Ascomycetes for this flora. After his death in 

 May 1904, his son, Ernest Feltgen, continued the work, and has 

 published a further instalment. The substratum, locality, and date of 

 growth are given in each case, and many new species are described. 

 There are also included full descriptions of many rare forms. 



Biology of Pyronema confluens.f — P. Kosaroff found that this 

 fungus appeared constantly on burnt soil, and he made a series of 

 culture experiments to determine the conditions favourable or unfavour- 

 able to its growth. He failed to induce growth on unsterilised soil, and 

 concluded that there must be some poison in such soil which hindered 

 the development of the fungus. Its frequent appearance on burnt 

 ground must be due to the effects of heat and sterilisation, as charcoal 

 alone was not sufficient to insure a growth. 



Ergot.| — E. Tschermak discusses the appearance and prevalence of 

 this disease in cereals. The sclerotium makes its appearance in the 

 flower whether fertilised or not. In rye-plants that have a prolonged 

 flowering season (as in winter rye), the number of infected plants tends 

 to be much greater than in those with quick flowering. In barley the 

 naked varieties suffer more than those with glumes. The conditions of 

 moisture and temperature at the flowering period have much to do with 

 the spread of the fungus. In a dry season and on dry soil, the time of 

 flowering passes quickly, and the risk of infection is correspondingly 

 diminished. 



Production of Stable Yeasts from Fungi.§ — G. Odin, who had 

 already produced yeasts from Penicillium and Coremiwn, has continued 

 his experiments with other fungi — Sterigmatocystis versicolor and Asper- 

 gillus fumigatus. He obtained the yeasts by cultivating the spores of 

 the fungi in a sugar solution contained in a sealed chamber. The yeasts 

 so developed were transferred to carrot or potato, and did not revert to 

 the filamentous condition. He tested the effect of the yeasts of 

 A. fumigatus, which is known to be pathogenic on rabbits, etc., and 

 found that they retained unimpaired the pathogenic properties of the 

 parent stock. 



* Beilage Ber. Ver. Luxemburger Natur., xv. (1905). See also Bot. Centralbl., 

 cii. (1906) pp. 197-8. 



t Arb. k. Biolog. Anst. Land. Forstw., v. (1905) p. 126. See also Ann. Mycol., 

 iv. (1906) pp. 375-6. 



\ Fubling's Landw. Zeit., Iv. (1906) pp. 194-9. See also Ann, Mycol., iv. (1906) 

 pp. 369-70. § Comptes Rendus, cxliii. (1906) pp. 468-70. 



