ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
657 
late the free nitrogen of the atmosphere through the agency of tubercle- 
microbes ; but the extent to which this faculty exists varies in different 
plants belonging to the order. 
Action of the Water of the Soil on Vegetation.* — Pursuing his 
investigations on this subject, M. E. Gain states that the growth of the 
root is especially influenced by the quantity of moisture contained in 
the soil. When once the seed has begun to swell, the amount of water 
required for germination is very small. The flowering of a plant is 
retarded by a dry soil or by a moist air, while it is hastened by a dry 
air or by a moist soil. For the production of ripe fruit a certain desic- 
cation is necessary. 
(3) Irritability. 
Sleep of Plants.^ — Prof. E. Stahl discusses Darwin’s interpretation 
of the nyctitropic position of the leaves of plants, viz. that its purpose 
is to protect the leaf from nocturnal radiation. He considers, on the 
contrary, that its main object is to promote transpiration in the night 
and early morning. It is especially marked in those plants (Leguminosae, 
Oxalideae) in which the position of the leaves is unfavourable to trans- 
piration during the day. 
(4) Chemical Changes (including Respiration and Fermentation). 
Albuminoids as Products of Assimilation.^ — As the result of a 
series of experiments, made chiefly on Vitis vinifera and V. labrusca, Herr 
W. Sapoznikow claims to have demonstrated that the albuminoids are 
a direct result of assimilation, being formed, along with the carbohydrates, 
within the chlorophyll-bodies. For the formation of the former, the 
presence of nitrates is indispensable ; and, by increasing the amount of 
these salts and decreasing the intensity of the illumination, the formation 
of carbohydrates can be diminished or even entirely suppressed. The 
author suggests the idea that the albuminoids are the first product of 
assimilation, the carbohydrates resulting from their decomposition. 
Action of Alkaloids on Plants in the Dark and in the Light.§ — As 
the result of a series of experiments on the action of alkaloids on the 
growth of Lemna minor and Elodea canadensis, Sig. A. Marcacci says 
that the action of different alkaloids is not uniform. While quinine 
arrests the transformation of starch into saccharose and of dextrose into 
levulose without the action of light, strychnine produces the same effect 
only with the assistance of light, and morphine does not completely 
arrest it even in the presence of light. From these facts the author 
draws the conclusion that the hydrating processes are not simple 
chemical processes, but are dependent on other forces as yet insufficiently 
recognised. 
Migration of Phosphate of Lime in Plants. || — M. L. Vaudin 
believes that he has determined in what condition phosphate of lime 
* Ann. Sci. Nat. (Bot.), xx. (1895) pp. 63-215 (4 pis. and 19 figs.). Cf. this 
Journal, ante , p. 452. f Ber. Deutsch. Bot. Gesell., xiii. (1895) pp. 182-3. 
I ‘ Eiweissstoffe u. Kohlenhvdrate d. griinen Blatter als Assimilationsproducte,’ 
Tomsk, 1894, 61 pp. and 1 pi. (Russian). See Bot. Centralbl., lxiii. (1895) p. 246. 
Cf. this Journal, 1892, p. 235. § Nuov. Giorn. Bot. Ital., ii. (1895) pp. 222-7. 
|| Ann. Inst. Pasteur, ix. (1895) pp. 636-42 ; Comptes Rendus, cxxi. (1895) 
pp. 362-4. 
1895 2 x 
