657 
ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
the same time in the juices of certain fungi, e.g. Russula cyanoxanthci 
and R. delica. 
Importance of Potassium and Magnesium for the Growth of 
Fungi.* — Herr W. Benecke gives the details of a large series of experi- 
ments, which confirm the conclusion, at which he had previously arrived, 
of the absolute necessity of these elements for the development and 
growth of the lower fungi. The species chiefly experimented on was 
Aspergillus niger. 
Saprolegniacese, Ancylistese, and Chytridiaceae.f — Herr A. Maurizio 
gives a monograph of the Swiss species of these families of Fungi, to- 
gether with a description of a new species belonging to the last, Olpidi- 
opsis major , parasitic on Saprolegnia Thureti. The author agrees with 
Fischer in the statement that the hyphse of the Chytridiaceae cease to 
grow after infection ; but does not confirm his observation that the spores 
are in general produced only where the hyphm enter the host-plant. 
The sporanges (in 0. major ) are developed only at the thickened ends 
of the liyphae, to which there is a strong current of protoplasm from 
their lower portion and the contents of which display a plasmode-like 
movement. 
Leptomitaces.J — Mr. B. Thaxter describes this family of Sapro- 
legniaceae, composed of the genera Gonapodya , Leptomilus, Apodachlya , 
Rhipidium, distinguished by its enormously large basal cell, Sapromyces, 
and a new genus Araiospora, intermediate between Rhipidium wad. Sapro- 
myces, with the following diagnosis : — Plant consisting of a greatly 
enlarged basal cell attached by rhizoids from its base, and similar in 
character to the segments of the filaments which arise, often in consider- 
able numbers, from its distal extremity. Filaments repeatedly umbel- 
lately branched, cylindrical or nearly so. Zoosporanges arising from 
the distal end of the segments, in whorls or umbels of two kinds, the 
one smooth, the other differently shaped and furnished with prominent 
spines* Zoospores finely granular, biciliate, monoplanetic, emerging in 
a mass at first surrounded by a thin membrame which ruptures almost 
immediately. Ooogones in whorls or umbels, often associated with the 
zoosporanges, spherical, separated from the segment, like the zoo- 
sporanges, by a constriction. Oosperms solitary, thick-walled, sur- 
rounded by an envelope derived from the periplasm. Antheridial 
branches arising from special segments, simple or branched, the small 
rounded antherids applying themselves close to the base of the oogone. 
The following new species are also described : — Rhipidium ameri- 
canum, Araiospora pulchra, Sapromyces androgynus. 
Structure and Reproduction of Cystopus.§ — Mr. H. Wager has 
studied in detail the life-history of Cystopus candidus, belonging to the 
Mucorini. The gonidanges are produced on basids, which are formed 
in large numbers beneath the epiderm of the stem, leaf, and seed-vessel 
of the host-plant. The formation of conids is not jneceded either by 
fusion or by division, as is the case in the Basidiomycetes and Ascomy- 
* Bot. Ztg., liv. (1896) l te Abt., pp. 97-132. Cf. this Journal, 1895, p. 545. 
f JB. Naturf. Gesell. Graubiioden, 1895, 30 pp. and 1 pi. See Bot. Centralbl., 
lxvii. (1896) p. 134. % Bot. Gazette, xxi. (1896) pp. 317-31 (3 pis.), 
§ Ann. Bot., x. (1896) pp. 295-342 (2 pis.). Of. this Journal, ante, p. 335. 
