562 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Algae. 
Food-Material of Algae and Fungi.* * * § — Dr. T. Bokorny gives the 
results of a series of experiments on the limits of dilution of sub- 
stances which can be taken up by the lower plants. Among the more 
noteworthy are the following : — In a 1 : 100,000 solution of fuchsin, 
Mesocarpus and Spirogyra became strongly coloured, and soon died ; a 
solution of 1 : 1,000,000 produced no effect. In a 1 : 100,000 solution of 
potassium biniodide, starch-grains assumed a violet tint in 24 hours ; 
with a solution of 1 : 500,000, the starch-grains were not coloured, but 
the cells ( Spirogyra ) were killed. Caffein produces the aggregation- 
reaction in the protoplasm with a dilution of 1 : 10,000 ; ammonia pro- 
duces the same result with a dilution of 1 : 100,000. A proportion of 
1 : 100,000 of a mixture of potassium phosphate, magnesium sulphate, 
and calcium nitrate in water is sufficient to afford a supply of the neces- 
sary mineral ingredients of the food of Algae. 
Arboreal Algse.l — Among a collection of Algae gathered on trees in 
Samoa, Herr W. Schmidle finds the following new species Phycopeltis 
microcystis, Hansgirgia polymorpha , and H. irregulare, all on leaves ; also 
the following : — 
Dendronema confervaceum g. et sp. n. Cellulae minim ae, 2-3 p latae, 
6-12 p longae, cylindricae et utrinque rotundatae, aut raro longe ellipticae, 
vix se attingentes, et praecipue materia firma hyalina non v. vix visibili 
in filum breve conjunctae ; fila simplicia, aequicrassa, paucicellulata, 
foliis Muscorum Hepaticorum aut Scytonematibus basi affixa, patentia, 
plerumque appropinquata, raro singula ; contentus chlorophyllosus (ut 
videtur) axialis, membrana pro ratione firma ; pyrenoidibus et nucleolis 
adhuc ignotis ; multiplicatio zoogonidiis rima e cellula effugientibus (ut 
videtur). Epiphytic on Hepaticae. 
Fossil Algae. | — Herr A. Rothpletz classifies the Fucoideae (or 
probably rather the Phaeophyceae) of the Flysch under six genera, viz. 
Phycopsis (including Chondrites , Chondrides , and Gigartinites ), Granularia 
(including Halymenites, Caulerpa , and Miinsterici), Keckia , Squamularia , 
Gryllophyllites, and Taonurus. A new genus, Siphonothallus , is also 
described, belonging apparently to the Siphoneae. 
New Marine Algae.§— Herr P. Kuckuck gives a more detailed 
description of the newly discovered genus Milcrosyphar from Kiel and 
Heligoland, with two new species, M. Porphyrse and M. Polysiphonise , 
growing on the respective seaweeds from which they are named. Two new 
species of PhaBosporeae are also described, Ectocarpus lucifugus and Lepto- 
nema lucifugum, growing in dark hollows, as well as other new species of 
Phaeosporeae and Florideae, and a new genus of Chlorophyceae, Sporo - 
cladus , resembling a small Cladophora, and developing sporanges from 
the terminal cells of primary and secondary branches, containing from 
* Biol. Centralbl., xvii. (1897) pp. 417-23. 
+ Hedwigia, xxxvi. (1897) pp. 277-87 (4 pis.). 
X Zeitschr. Deutsch. Geol. Gesell., 1896, pp. 854-914 (3 pis.). See Bot. Cen- 
tralbl., lxxi. (1897) p. 71. 
§ Beitr. z. Kennt. d. Meersalgen, 42 pp. and 7 pis. ; also Bemerk. z. marinen 
Algen -vegetation v. Helgoland, ii., 28 pp. and 21 figs. See Bot. Centralbl., lxxi. 
(1897) pp. 96 and 311. Cf. this Journal, 1896, p. 91. 
