ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
823 
Dot consider it certain tliat this assimilation of free nitrogen is effected 
directly by the fungus itself ; it may rather be the result of an irri- 
tation of the host -plant by which its tissues are excited to more active 
powers. 
Peas, red clover, and many other leguminous plants possess, there- 
fore, the property, which is so valuable to agriculture, of returning 
to the soil, on the decay of their tissues, a larger amount of nitrogen 
than they have taken from it ; and some non-leguminous plants have 
the same faculty, though to a much smaller extent. 
Assimilation in the Sun and in the Shade.* * * § — From a series of ex- 
periments made on several woody and herbaceous plants, M. L. Geneau 
de Lamarliere states that, under the same external conditions the in- 
tensity of the decomposition of carbon dioxide varies in leaves of the 
same species, according to their conditions of development, the process 
being more energetic in those developed in the sunshine than in those 
developed in the shade. 
Accumulation of Atmospheric Nitrogen by Bacillus radicicola.f — 
Fresh experiments on the inoculation of Vicia Faba by this microbe 
lead M. W. Beyerinck to the conclusion that, under favourable 
conditions as regards nutrition and temperature, there is a gain in the 
amount of nitrogen, though it is in all cases but slight. With the 
Fobinia bacilli no positive results were obtained. Whether the nitrogen 
gained from the air was in the free or combined state is not certain, but 
the latter is the more probable. Some micro-organisms have the power 
of withdrawing nitrogen compounds from solutions so dilute that the 
roots of higher plants are unable to extract anything from them. The 
nitrogenous food of the Papilionacese must depend entirely on the dying 
otf of the bacteria in the nodules, as only dead bacteroids seem able to 
give up as albumen the nitrogen they took up. 
Periodicity of Transpiration.^ — Experiments made by Herr W. 
Broocks on a number of cultivated plants show that the dry substance 
of the green leaves of plants growing in the open air increases during 
the day in summer, except when the temperature is low and the sky 
cloudy. When the sky is clear the greatest increase takes place between 
6 a.m. and 12, or between 10 a.m. and 2 p.m. ; the hour between 11 and 
12 generally showing the maximum of all. During the night there is 
always a decrease in the dry weight of the leaves, which is most rapid 
when the temperature is high. The greater part of this decrease takes 
place during the early part of the night. 
Transpiration from the Flower. §— From experiments on Galtonia 
candicans , Fuchsia coccinea , and Anemone japonica , M. G. Curtel states 
that in the young condition of the bud transpiration is very strong, but 
decreases subsequently, reaching a minimum when the bud is about half 
developed. At this time the epiderm has become greatly thickened, and 
* Comptes Rendus, cxv. (1892) pp. 368-70. 
f Med. Kon. Akad. Wetens. Amsterdam, viii. pp. 460-75. See Journ. Chem. 
Soc., 1892, Abstr., p. 1019. 
X ‘Ueb. tagliche u. stundliche Assimilation einiger Cultur-Pflanzt n,’ Halle, 
1892 (56 pp.). See Bot. Centralbl., li. (1892) p. 182. 
§ Comptes Rendus, cxiv. (1892) pp. 847-9. 
