312 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
cellular spaces of the layers of pith and cortex adjoining the wounded 
surface. 
Transpiration of Tropical Plants.* * * § — Herr A. Burgerstein gives the 
result of observations on the transpiration of plants growing in the hot 
moist climate of Java when protected both from direct insolation and 
from rain. He does not confirm the statement of Haberlandt that in 
these conditions the amount of transpiration is much less than in the 
temperate climate of Central Europe. 
(3) Irritability. 
Periodic Movements of the Leaves of Mimosa in the Dark.f — From 
a series of observations on the periodic movements of the leaves (chiefly 
of Mimosa pudica) in the dark, Herr L. Jost comes to the conclusion that 
they are dependent entirely on changes in temperature ; the effect being 
tho reverse of that which takes place in the case of flowers. An increase 
of temperature induces the nocturnal, a decrease of temperature the 
diurnal position. The phenomena are the same with etiolated as with 
green leaves. 
Growth and Curvature of Phycomyces.J — According to M. G. Bullot, 
the following laws govern the growth and curvature of the sporangio- 
phores of Phycomyces niiens. At the commencement of the heliotropic 
or geotropic curvature, there is no accumulation of protoplasm on the 
concave or decrease on the convex side of the filament ; these take place 
only at a later period of the curvature. When two mycelial filaments, 
at any period of their development, come into contact with one another, 
their growth is at once or very quickly arrested, and the apices of the 
filaments become gradually more slender. The sporangiophores grow 
more rapidly in a continuous light than in the dark. 
(4) Chemical Changes (including Respiration and Fermentation). 
Formation of Diastase,§ — Prof. W. Pfeffer describes the result of 
experiments made for the purpose of determining the conditions under 
which diastase is formed in plants. The subjects were Penicillium glau- 
. cum , Aspergillus niger , and Bacterium megaterium. An increase in the 
amount of sugar in the substratum had always the effect of decreasing the 
production of diastase ; but this result was not produced when the sugar 
was replaced by another carbohydrate or by glycerin or tartaric acid. 
The arrest in the production of diastase is not a purely chemical or 
physical phenomenon ; it is rather a phenomenon of irritation exerted on 
the organism by a solution of sugar of a certain degree of concentration. 
Germination of the Almond. || — M. Leclerc du Sablon states that the 
changes which take place in the germination of the almond conform to 
those which are characteristic of oily seeds in general. The oil is 
gradually digested, a certain quantity of fatty acids being at the same 
time set at liberty. The chief product of the decomposition of the oil is a 
* Ber. Deutsch. Bot. (resell., xv. (1897) pp. 154-65. 
t Bot. Zlg., lv. (1897) pp. 17-48 (5 figs.). 
i Aim. Soc. Beige Microscopie, xxi. (1897) pp. 61-93 (1 pi. and 1 fig.). 
§ Ber. K. Sachs. Ges.'Wiss. Leipzig, 1896 (1897) pp. 513-8. 
|| Iiev. Gen. de Bot. (Bonnier), ix. (1897) pp. 5-16. Cf. this Journal, 1895, p. 551. 
