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POPULAR SCIENCE REVIEW. 
mycelium-filament, whence it originates, with its apex pressed towards it. 
The male organ of fructification consists of two filiform antheridial cells 
proceeding from the base of the oogonium. 5. After fertilisation several 
oogonia in union give rise to the formation of a receptacle. The oogonia 
are included in the dense filamentous tissue wliich forms the first rudiments 
of the receptacle, without (as it appears) their imdergoing any transformation. 
6. The stem is that part of the receptacle which is first produced, afterwards 
the pileus. This is at first regular, horizontal, and attached to the stem by 
the middle of the under surface, afterwards it becomes oblique, vertical, and 
attached to the stem in the neighbourhood of the margin. 
Development of Cellular Tissue in the Spiral Vessels. — It was announced 
many years since by Herr Schleiden, that the filling up of the air spaces of 
the spiral tissue which occurs in certain plants as they increase in age, was 
due to the multiplication of the contiguous cells, and not to development of 
cells vdthin the spirals. Subsequently the opinion was decidedly opposed 
by Herr Bohm. It is therefore of interest to note that, in a paper recently 
read before the Academy of Sciences of Vienna, Herr Unger conclusively 
showed that Herr Schleiden’s view is correct. Herr Unger attributes the 
multiplication of the cells to the influence of the oxygen which enters the 
tissues from the atmosphere. — Vide D Institute No. 1784. 
Colouring Matter from Decayed Wood . — Some four or five years ago M. 
Uordos called attention to a green colouring matter which he had obtained 
from dead wood. M. Bommier has now come to investigate this substance, 
and has found, what we are surprised was not thought of before, that the 
new substance is a species of fungous growth, and does not really proceed 
from the decaying wood. M. Bommier thinks his green substance is dis- 
tinct from that described by M. Fordos, and he gives it the name of Xylin- 
deine. He states that it differs from the old substance xylochloric acid, in 
that it resembles indigo in undergoing reduction in the presence of alcohol, 
potass, and glucose. It has also the valuable property of being easily fixed, 
and thus forming a dye of a brilliant blue-green colour, resembling Chinese 
green. The oak is the tree on which this substance is most frequently met, 
but it is occasionally found on other trees also. For a detailed account of 
its mode of preparation, vide Comptes Dendus, January 13. 
Absorption of Gases by Plants. — M. Lechartier, following up Van 
Tiegehm’s researches, has discovered one or two facts of interest with 
regard to the absorption of air by aquatic plants. The experiments were 
carried out upon the water-lily (Nymphaea), and are fully recorded in his 
published paper. The result seems to be this. The gas contained in the 
stem is richer in carbonic acid than the gas found in the petiole. Even at 
the same point in the interior of the plant, the quantity of carbonic acid 
diminishes, and that of oxygen increases in proportion according as the solar 
action is prolonged. But the same difference in composition is always ob- 
served between the gas which is evolved by the petiole, and that which is dis- 
engaged by the deeper parts. The general conclusion would seem to be, that 
the gases are absorbed in the deeper parts, and exhaled by the more super- 
ficial tissues.— Vide Comptes Rendus^ t. Ixv, No. 26. 
