338 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
In fine, the lactic fermentation is influenced by a great number of 
factors, and is subject to a multiplicity of variations. 
Liberation of Oxygen demonstrated by Bacteria.* * * § — Prof. Th. W. 
Engelmann publishes figures illustrating the use of the method which 
he employed in 1881 in studying the liberation of oxygen from green 
cells. As is well known, he used Bacteria whose movements and 
distribution furnished an index to the liberation of oxygen. The point 
of the present paper is the plate. 
B. CRYPTOGAMIA. 
Cryptogamia Vascularia. 
Adventitious Buds of Cystopteris bulbifera.f — Herr S.'Rostowzew 
gives a detailed description of the structure and mode of germination of 
the buds produced on the fronds of this fern. Their formation acts 
prejudicially on the development of the spores, which, though produced 
in large quantities, were found to be incapable of germination when 
adventitious buds were borne also on the same frond. 
Growth of Arborescent Lepidodendra.J — Prof. W. C. Williamson 
gives a very full account of the present state of our knowledge 
respecting the growth and development of the Carboniferous Arbor- 
escent Lepidodendra, and arranges under a number of different types 
the variations hitherto observed in their structure. The comparison of 
a very large number of sections induces the author somewhat to modify 
his previous view of an enlargement of the primary xylem proceeding 
from above downwards. 
Roots of Calamites.§ — Acccording to Prof. W. C. Williamson and 
Dr. D. H. Scott, the fossils hitherto described under the name of 
Astromyelon Williamsonis &ve the adventitious roots of Calamites. Their 
structure is in all respects that of roots, as is shown by the centripetal 
primary xylem, the alternating strands of primary xylem and phloem, 
the endogenous mode of branching, and the absence of nodes. 
Muscineae. 
Respiration and Assimilation of Mosses. || — According to Herr B. 
Jonnson, the intensity of respiration and assimilation varies greatly in 
different species of moss. Those which grow in moist situations show 
a much greater energy than the xerophilous species. The red colour 
characteristic of mosses exposed to a strong insolation causes a diminution 
in the intensity both of respiration and of assimilation. 
Rabenhorst’s Cryptogamic Flora of Germany (Musci).— Parts 24, 
25 of this work, edited by Herr K. G. Limpricht, complete the account 
* Arch. Neerland. Sci., xxviii. (1894) pp. 358-71 (1 pi.). Cf. this Journal, 1881, 
p. 962. 
f Ber. Deutscli. Bot. Gesell., xii. (1894) Gen.-Vers.-Heft, pp. 45-57 (1 pi.). Cf. 
this Journal, 1894, p. 595. 
t Mem. Manchester Lit. and Phil. Soc., ix. (1894-5) pp. 31-65. 
§ Proc. Roy. Soc., lvii. (1894) pp. 1-3. 
|| Bot. Notiser, 1894, p. 152. See Hedwigia, xxxiv. (1894), Rep., p. 25. 
