ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
509 
Thermotropic Movement of the Leaves of Rhododendron maxi- 
mum.* — Dr. J. W. Harshberger describes the movements of the leaves 
of this evergreen shrub, which can be followed out in cut branches stuck 
into the soil in pots. Under a low temperature the petiole takes a sharp 
bend downwards through an angle of about 70° ; the lower side of the 
petiole is puckered into transverse folds, and the leaves are rolled 
tightly inwards in a convolute manner, so that the upper epiderm only 
is exposed. They are thus protected against excessive transpiration, 
and snow and ice are readily thrown off. The author attributes the 
movements to the gradual passage of sap through the contractile proto- 
plasmic sac of each cell into the intercellular spaces, or to the movement 
of the liquid from cell to cell by means of the protoplasmic bridges. 
(4) Chemical Changes (including Respiration and Fermentation). 
Decomposition and Formation of Albumen in Plants.y — From 
experiments on Pisum sativum , Vicia Faba, and Lupinus luteus^ M. N. 
Prianischnikow derives the following general conclusions. The process 
of decomposition of albumen has a “ great period,” and is characterised 
by a “ great curve ” of its own. The process of accumulation of aspara- 
gin has also a great curve ; and the maxima of the two curves coincide 
nearly or completely. These two curves attain their maxima some 
days earlier than that which expresses the elimination of carbon dioxide. 
At the close of the period of germination, the energy of the accumu- 
lation of asparagin — or rather the accumulation of the nitrogen of aspa- 
ragin — exceeds the rapidity of the passage of the nitrogen of albumen 
into the form of other combinations. 
Production of Alcohol in Plants. — From observations made on 
wheat and hazel, M. Berthelot J finds that, under normal conditions 
of respiration and assimilation, minute quantities of alcohol are pro- 
duced in the tissues of plants, probably formed from the decomposition 
of carbohydrates, in a similar way to that in which methyl-alcohol is 
sometimes produced. 
M. P. Maze § corroborates these results, and believes that the alcohol 
is formed in the living cells at the expense of the glucoses by a normal 
diastatic process. 
Diastatic Function of Indigoferous Plants. || — From experiments 
made on Isatis alpina , M. L. Breaudat concludes that, in those species 
of Indigofera and Isatis which yield indigo, the presence of alkaline 
bases or those of the alkaline earths, or their soluble or insoluble 
carbonates, is necessary for the formation of indigo ; while that of acids 
or neutral salts inhibits it. The oxidising power of the soluble oxydase 
contained in the sap is but very feeble ; but this power is increased by 
the presence of alkalies and alkaline carbonates. 
Nitrification of Organic Nitrogen.lf — Herr W. Omelianski states 
with simple directness that the work of Frankland, Warrington, 
♦ Proc. Acad. Nat. Sci. Philadelphia, 1899, pp. 219-24 (3 figs.), 
t Ber. Deutsch. Bot. Gesell., xvii. (1899) pp. 151-5. 
t Comptes Rendus, cxxviii. (1899) pp. 1366-70. § Tom. cit., pp. 1608-10. J 
|| Tom. cit., pp. 1478-80. Cf. this Journal, ante , p. 181. 
if Centralbl. Bakt. u. Par., 2 10 Abt., v. (1899) pp. 473-90. 
1899 2 m 
