522 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
legninas. After a full account of their structure and life-history, the 
Saprolegninae are classified under the two families Saprolegniaceae and 
Monoblepharidacese. The Saprolegniaceae comprise the genera Pythiopsis, 
Saprolegnia (9 species classified under an asterophora, a ferax , and a 
monilifera group), Leptolegnia , Achlya (9 species), Aphanomyces , Dic- 
tyuchus , Aplanes , Apodya , Apodachlya, and Bhipidium. The Mono- 
blepharidaceae are made up of Monoblepharis, and a new genus separated 
from it, Gonapodya. 
Effects of Mechanical Movement on the Lower Fungi.* * * § — Mr. H. L. 
Russell has carried out a series of experiments on the effects of con- 
cussion on the growth of some low organisms — Monilia Candida, Oidium 
albicans , and SaccJiaromyces Mycoderma. He finds that constant agitation 
affects very strongly the increase in number of the cells formed, and con- 
sequently the amount of organic matter produced, the increase in growth 
amounting to as much as from 200 to 300 per cent. The formation of 
hyplial filaments is, on the other hand, retarded by constant movement, 
and the amount of fermentation products, as determined by the alcohol 
formed, undergoes a sensible diminution. The cause of the more rapid 
cell-multiplication appears to be chiefly the greater aeration of the 
culture. 
Massee’s Phycomycetes and TJstilagineae.f— In this volume Mr. G. 
Massee gives a general account of the structure of three groups of 
Fungi, the Mucorini, Peronosporese, and Ustilagineae, followed by a 
diagnosis of all the British genera and species. 
Retarded Germination of iEcidiospores. J — M. G. Poirault records 
an instance of the germination of the eecidiospores of Bcestelia cancellata 
at periods varying from one to two weeks after they had been placed in 
suitable conditions, contrary to what had previously been observed to be 
the case with aecidiospores. The same spores had previously withstood 
a low temperature of — 7° to — 8° C. 
Parasitic Fungus on the Lombardy Poplar. §— M. P. Vuillemin 
gives further details of the life-history of Didymosphseria populina, a 
parasitic fungus belonging to the Pyrenomycetes, which has caused great 
destruction to the Lombardy poplar during recent years in the north of 
Europe and of America. He supports the view of Moebius II that con- 
tinual non- sexual propagation of a species is not necessarily fatal to its 
vigour ; and attributes the liability to disease of this variety of the 
poplar, which has never been propagated in any other than a non-sexual 
manner, to a succession of severe winters, followed by wet summers, 
which have been specially favourable to the development of the parasite. 
Gnomonia erythro stoma IF — Herr B. Frank has studied the life- 
history of this parasitic fungus, which attacks both the sweet and the 
* Bot. Gazette, xvii. (1892) pp. 8-15. 
t ‘ Brit. Fungi : Phycomycetes and Ustilagineae ’ (8 pis.), London, 1891. See 
Grevillea, xx. (1891) p. 45. 
X Journ. de Bot. (Morot) vi. (1892) pp. 59-60. 
§ Rev. Mycol. xiv. (1892) pp. 22-7 (1 pi-)- Cf. this Journal, 1889, p. 681. 
1| Cf. this Journal, 1891, p. 494. 
■fi Zeitschr. f. PflanzenkraDkheiten, i. (1891) pp. 17-24, See Bot. Centralbl., xlix. 
(1892) p. 339. 
