146 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
In tlieir works on the micro-organisms of nitrification Herren A. 
Stutzer and B. Hartleb * * * § have alluded to a mould-fungus characterised 
by a much-branched mycele, and by having both mega- and microspores. 
In the three stages of development the fungus exerts different actions. 
Hence, for exciting definite effects, the composition of the medium and 
the presence or absence of atmospheric air are of great importance. 
Under certain circumstances the fungus lives on organic nitrogenous 
compounds, and is then able to set up nitrification directly, under other 
conditions to produce nitrite, and under still others nitrate. The mycele 
may split up into indifferent cells which resemble bacteria. 
B. CRYPTOGAMIA. 
Muscineae. 
Rhynchostegium.f — Sig. U. Brizi gives a monograph of this genus 
of Musci, which he divides into two subgenera, Eurhynchostegium and 
Eiirhyncliium. Twenty-eight species in all are described, with a large 
number of sub-species and varieties. There are two new species, 
B. romanum and Pirottse. 
Itabenhorst’s Cryptogamic Flora of Germany (Musci>4 — Parts 
28-30 of this important work by Herr K. G. Limpricht are still occupied 
with the Hypnacese. After the completion of Brachythecium , the 
following genera are treated of : — Bryhnia (1 sp.) ; Seleropodium (4 sp.) ; 
Hyocomium (1 sp.) ; Eurhynchium (21 sp.) ; Bhynchostegiella gen. n. 
(5 sp.), with the following diagnosis : a central bundle, leaves narrowly 
lanceolate, not or scarcely decurrent, basal cells not broadened, rib 
single, cells of the leaf-wings not or scarcely different from the basal 
cells, stomates 2-celled, epidermal cells collenchymatous, seta curved, 
usually warty ; Bhynchostegium (6 sp.) ; Bliapliidostegium (2 sp.) ; 
Thamnium (2 sp.). The third group, Hypnese, then follows, consisting 
of the genera Plagiothecium , Amblystegium , Hypnum , and Hyloconium , 
and a commencement is made of Plagiothecium with 18 species. 
Development of Geothallus.§ — Pursuing his investigations into this 
new genus of Hepaticee, Prof. D. H. Campbell describes in particular the 
germination of the spores and bulbils, and the structure of the antherid 
and archegone, as well as that of the sporogone. He regards the genus 
as most nearly allied to Sphserocarpus , agreeing both with that genus 
and with Biccia in the form of the apical cell, and the general position 
and structure of the sexual organs, including the characteristic envelope 
with which each is surrounded. In the structure and development of 
the sporogone there is a close resemblance between Sphserocarpus and 
Geothallus. Geothallus differs from Sphserocarpus chiefly in the more 
massive thallus, the sessile archegone, the development of true leaves, 
and the formation of bulbils by which the plant becomes perennial. 
It has also some affinities with Fossombronia, and may be regarded as 
intermediate between that genus and Sphserocarpus. 
* Centralbl. f. Bakteriol. u. Parasitenk., 2 te Abt., ii. (1896) p. 701. 
f Malpighia, x. (1896) pp. 227-57, 437-78 (1 pi.). 
X Cf. this Journal, 1896, p. 212. 
§ Ann. Bot., x. (1896) pp. 489-510 (2 pis.). Cf. this Journal, 1896, p. 441. 
