ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
G49 
and some other species), although they may attain a length of 50 cm. 
and live for several years, cease to grow after the first year. 
Growth of Banana-Leaves.* * * § — Mr. W. Maxwell gives tables of the 
rate and mode of growth of the leaves of the banana at Honolulu. The 
total daily increase in length was in some cases as much as 8 in. The 
action of direct sunlight, and the direction and force of the wind appear 
to be more potent factors in increasing or arresting growth than small 
variations of temperature. 
Assimilation of Elementary Nitrogen and of Lecithin by Plants. — 
Herr J. Stoklasaj states that, in unsterilised soil, in which algm and 
bacteria increase the amount of nitrogen used up in the first develop- 
ment of the plant, lupins assimilate an equal quantity of elementary 
nitrogen, whether they have root-tubers or not. In sterilised ground, 
the amount assimilated is increased eightfold by infection. At the 
time of flowering, the root-tubers of Leguminosae were found to contain 
3 ‘99 per cent, nitrogen in the form of proteids, 0*35 per cent, in the 
form of amides; after the ripening of the fruit only 1*54 per cent, in 
the form of proteids, 0 • 15 per cent, in the form of amides. From the 
leaves the amides are carried to the tubers, where they are transformed 
into proteids by the action of glucose, these proteids accumulating there 
in great quantities, and forming the food-material for the bacteria. In 
Polygonum Fagopyrum he states that the quantity" of nitrogen contained 
in the seeds is not sufficient for the normal development of the assimi- 
lating organs. The organ for the assimilation of nitrogen is the 
chlorophyll-granules. 
In another paper f the same author establishes the importance of the 
formation of lecithin for the vital processes of plants, and demonstrates 
apparently for the first time the assimilation of phosphoric acid in an 
organic form (oat). The formation and destruction of chlorophyll 
proceed pari passu with the appearance and disappearance of lecithin. 
This substance is produced in green leaves exposed to light ; disappearing 
again in the dark ; in other words, the formation of lecithin is connected 
in several ways with the assimilation of carbon dioxide. 
Herr J. H. Aeby § confirms the conclusions of Pfeiffer, Franke, 
Nobbe, and Hiltner, that white mustard differs from leguminous plants 
in being unable to fix the free nitrogen of the atmosphere. 
Arrest of Assimilation,|] — Mr. A. J. Ewart has performed a series 
of experiments on the power of certain agencies — dry and moist heat, 
cold, desiccation, partial asphyxiation, etherisation, treatment with acids, 
alkalies, and antipyrin, accumulation of the carbohydrate products of 
assimilation, immersion in very strong plasmolytic solutions, prolonged 
insolation — to arrest assimilation in a number of green plants. The 
inability to assimilate is, if the cell remains living, only temporary. 
During the whole time of the arrest of assimilation, the cell continues 
to respire. In the great majority of cases no visible change in the 
* Bot. Gazette, xxi. (1896) pp. 365-70. 
f Landwirtk. Jahrb., 1895, pp. 827-63. See Bot. Centralb!., xlvi. (1896) p. 17. 
% SB. K. Akad. Wiss. Wien, civ. (1895) pp. 712-22 (1 pi.). 
§ Lanclwirtli. Vers.-Stat., xlvi. (1896) pp. 410-39. See Journ. Chem. Soc., 1896, 
Abstr., p. 381. || Journ. Linn. Soc. (Bot.), xxxi. (1896) pp. 364-461. 
