336 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
(3) Irritability. 
Movements of the Flowers of Cyclamen. * * * § — Herr F. Hildebrand 
describes the changes of position assumed by the flowers of Cyclamen 
between the opening and the closing. These vary in different species, 
and are shown not to be dependent on light. The most favourable position 
for the pollination of the stigma is obtained in some cases by a curving, 
in others by a twisting of the flower-stalk. With regard to the spiral 
curving of the flower- stalk, which brings the capsule in contact with the 
soil, it is observed that this sometimes takes place in one direction, 
sometimes in the other. 
Sensitive Organs of Leguminosse and Oxalidese.j — An examination 
of these organs by Mdlle. A. Rodrigue leads her to the conclusion that 
the primary cause of the movements resides in the protoplasm, and that 
this is not in all cases equally sensitive. The anatomical characters 
which, in the Leguminosae, correspond to the greater or less extent of 
the movements, are the more or less complete concentration of the vascular 
bundles in the motor organ ; the nature of its liber ; the more or less 
complete union of the bundles in the motor organ, or their separation ; 
and the nature of the protecting arc of the liber. 
Negatively Geotropic Roots.t — Dr. J. Eriksson records examples of 
negative geotropism in the roots of sand-plants ( Carex arenaria and 
liirta) i some of them taking a direction vertically upwards, obviously for 
the purpose of promoting the absorption of water. This corresponds to 
a similar phenomenon in the case of the aerial roots of epiphytes, and 
of the roots of some swamp-plants, such as Sonneratia and Avicennia , and 
of some palms. 
C4) Chemical Changes (including Respiration and Fermentation). 
Lactic Fermentation.§ — In the" 1 first part of his work M. E. 
Kayser points out the origin of the lactic ferments, their morphology, 
their physiological functions, and their distinctive characters in various 
media. After noticing the methods of culture, the differences in their 
resistance to heat in liquid media, the time it takes to coagulate the 
same milk at different temperatures, the acidity produced in the different 
media, and their resistance to desiccation, are touched upon. In the 
second part are considered — 
(A.) The reaction of the medium. The author finds that (1) the 
acidity, fixed and volatile, depends upon the particular microbe. (2) The 
acidity is much greater in a neutral medium. (3) For the same 
microbe the acidity depends entirely on the medium and the mode of 
culture. 
(B.) Influence of the duration of the fermentation. (1) The total 
acidity from certain ferments constantly increases ; in others it decreases 
at a given moment, finally increasing or oscillating around a certain 
limit. (2) The volatile acidity varies in the same way : it is specially 
* Bot. Ztg., liii. (1895) l te Abtheil., pp. 1-30 (1 pi.). 
t Arch. Sci. Phys. et Nat., xxxii. (1894) 3 pp. ; Bull. Soc. Bot. France, xli. 
1894, Sess. Extraord., pp. cxxviii-xxxiv. 
\ Bot. Centralbl., Ixi. (1895) pp. 273-9. 
§ Ann. Inst. Pasteur, viii. (1894) pp. 737-82. 
