670 SUMMARY OF CURRENT RESEARCHES RELATING TO 
these, passing through the pervalvar and the transapical axes, is the 
transapical plane. 
The author proceeds to define the different kinds of symmetry which 
may occur in the diatom-frustule, and gives a number of examples of the 
use of the terms which he proposes. 
Sporulation of Diatoms.* * * § — L’Abbe Count F. Casfracane records an 
example of the formation of spores within the frustule of Fragilaria 
crotonensis. The spores were very small, but showed a distinct nucleole. 
The number in each frustule was in most cases only two, though in some 
instances there were four, evidently resulting from the division of the 
two primary ones. 
Fossil Diatoms from the duirinaLy — Dr. M. Lanzi gives a list of 
about 70 fossil diatoms from the Quirinal. Their nature suggests that 
the deposit was in fresh or at most slightly salt water. 
Phycocyam.f — Herr H. Molisch has succeeded, in separating phy- 
cocyan from an Oscillatoria, probably 0. leptotricha, in the form of 
beautiful indigo-blue crystals, the chemical and physical reactions of 
which are given in detail. These show it to be of the nature of an 
albuminoid. 
jS. Schizomycetes. 
Assimilation of Free Atmospheric Nitrogen by Microbes. § — 
According to M. S. Winogradsky, the power of fixing atmospheric nitrogen 
is not the property of all microbes, but belongs to one form only, which 
he names Clostridium Pasteurianum, nearly allied to C. butyricum , and 
which he was able to isolate from other organisms of the soil. The 
nitrogen which is fixed is mainly in an insoluble organic form. Of 15 
other soil-microbes on which experiments were made, none was found 
capable of assimilating nitrogen ; nor were they able to utilise carbo- 
hydrates in the absence of combined nitrogen. 
Bacteriology of Water. |) — The fourth report of the Royal Society’s 
water research committee is occupied by an essay on the biology of 
Bacillus ramosus by Prof. H. Marshall Ward. This Schizomycete occurs 
at all seasons more or less, and forms on isolation plates white colonies 
which rapidly develop into large membranous growths. It seems to be 
commoner in the river water in autumn and winter than in spring or 
summer. Prof. Ward has succeeded in following out the life-history 
of this species in a singularly complete manner ; and as he finds the 
organism to be a remarkably typical and instructive one, he has thought 
it worth while to give in detail all the facts which have come under his 
observation, and especially to call attention to the fact that this species 
runs through its entire life-history from spore to spore-formation in 
from thirty to sixty hours at ordinary temperature. The author has, 
moreover, been enabled to follow the course of this life-history by 
continuous observation under powers (1/12 and 1/20 oil-immersions) 
* Atti Accad. Pontif. Nuovi Lincei, xlviii. (1895) pp. 87-8. Cf. this Journal, 
ante, p. 562. t Op. cit., xlvii. (1894) pp. 156-60. 
% Bot. Ztg., liii. (1895) l te Abt., pp. 131-5 (2 figs.). 
§ Arch. Sci. Biol., iii. (1895) pp. 297-352. See Journ. Chem. Soc., 1895, Abstr., 
p. 283. || Proc. Roy. Soc., lviii. (1895) pp. 265-468. 
