72 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Erysiphacese. — E. S. Salmon points out * that in our present know- 

 ledge of the life-history of this group of Fungi two great gaps exist : — 

 in the first place we do not know in what way every spring the asco- 

 spores give rise to the conidial or oidium-stagc ; and secondly, we do 

 not know to what extent each form of mildew is limited in its choice 

 of host-plants, and whether the same species, on different host-plants, 

 may not exhibit slight morphological characters correlated with its 

 occurrence on those plants. 



In a monograph of the order,f the same author describes 49 species, 

 in addition to a number of well-marked varieties, arranged in six 

 genera, — Podosphsera, Sphserotheca, Uncinula, Microsphsera, Erysiplte, 

 and Phyll actinia. He regards the ascus as the result of a true sexual 

 process, and does not support Dangeard's view that the fusion of the 

 nuclei in the young ascus is of sexual signification. Too much signifi- 

 cance must not be attached to the presence of appendages to the peri- 

 theccs. The memoir is accompanied by a very copious bibliography. 



Isaria arbuscula. j — J. Beauverie and C. Vaney give a description 

 of this fungus, parasitic on the larva of a Mexican cricket. The fungus 

 is characterised by its gigantic size as compared with the animal at- 

 tacked, reaching a height of b' cm. The fungus perforates the chitinous 

 coat of the insect, and forms a mycelial stroma in the tissues of the 

 host, finally completely destroying them and filling up the chitinous 

 -envelope. 



Parasitic Fungi. — In a collection of Fungi from Japan, E. S. Salmon § 

 finds a new species of Uncinula (Erysipheae) parasitic on Qucrcus glan- 

 duli f era, which he names U. septata. 



Under the name Oidium (jitri Aurantii, Dr. T. Ferraris || describes 

 a new parasitic fungus belonging to the Hyphomycetes, which is very 

 destructive to the orange crop in Italy. 



On the leaves of Euoiiymus japonicus, Prcf. G. Arcangeli % finds a 

 new species of Cicinnobolus, to which he gives the name C. Euonymi 

 japonici ; it is parasitic on the hyphae of another fungus, a form of 

 Oidium leucoconium. 



R. Aderhold ** has found the ascoform of Cercospora cerasclla, a 

 j)arasitic fungus which forms brown spots on the leaves of cherry trees, 

 and determines it to belong to the genus Nycopplistrella, naming the 

 species M. cerasclla sp. n. 



Expressed Yeast-cell Plasma. — Dr. A. Macfadyen, Dr. G. H. Morris, 

 and S. .Rowland ff summarise the results obtained by them as follows. 

 The top yeast of English breweries yields, by suitable treatment, a cell- 

 juice which possesses the transient power of decomposing sugar into 

 alcohol and carbonic acid. The amount of gas formed by an active 

 juice is as great as or even greater than that found by E. Buchner. 



* Journ. Quek. Micr. Club, vii. (1900) pp. 411-2. 



t Mem. Torrey Bot. Club, ix. (1900) 292 pp. and 9 pis. 



X Ann. tSoc. Linn. Lyon, xlvi. (1900) pp. 79-80. 



§ Journ. Bot., xxxviii. (1900) pp. 426-7 (0 figs.). 



j| Malpighia, xiii. (1900) pp. 368-81 (1 pi.). 



4 Atti Soc. Tosc. Sci. Nat. (Proc. Verb.), xii. (1900) pp. 108-10. 

 ** Ber. Dcutsch. Bot. Ges., xviii. (1900) pp. 24G-9. 

 tf Proc. Roy. Soc, lxvii. (1900) pp. 250-00. 



