EXTRACTS FROM FOREIGN PERIODICALS. 
10*2 
which the sleep of the corolla is due must be referred to an entirely different 
cause ; for it cannot be admitted that there was depletion of the cellular tissue 
plunged into the water. The experiment related above proves that it is the 
fibrous tissue contained in each nerve of the corolla which is the agent of the 
inward curvature, the incurvation which causes the sleep or shutting of the 
corolla. 
It must therefore be acknowledged, that in the nerves of the flowers of 
Mirabilis , the incurvation of sleep , or the incurvation of which the concavity is 
directed outwards, and which is due to the turgescence of the cellular tissue, 
first carries it by its force upon the incurvation of sleepy or that incurvation the 
concavity of which is directed towards the interior of the flower, and which is due 
to the action of the fibrous tissue; and that the incurvation of sleep , due to this 
latter tissue, becomes finally victorious. 
The incurvation outwards, which affects the cellular tissue during the immersion 
of the nerve in water, directs the curvature outwards when the nerve is plunged 
into syrup; this proves that here endosmose is the agent. But when the nerve, 
immersed in water several hours, has taken the second incurvation—that of sleep 
—it by no means loses it when transferred to the syrup; It is, therefore, not 
endosmose which occasions the incurvation of sleep. 
By reflecting on this singular phenomenon, I was led to believe that it was not 
without reason that Nature had lavished respiratory organs on the fibrous tissue, 
which is situated between two series of hollow organs filled with air. Since it 
was not by impletion of fluid that the fibrous tissue attained its state of curvature, 
it might be by impletion of oxygen. If this suspicion be well founded, the nerve 
which is immersed in aerated water, there first adopts outward incurvation, which 
is that of opening, and which afterwards takes the inward incurvation, or that 
of sleep, this nerve, I say, plunged into non-aeriated water, should always retain 
its first outward curvation, which is that of waking, an incurvation due to the 
endosmose of the cells of the cellular tissue; this nerve would thus never 
exhibit inward curvature, which is that of sleep, and which I believe to be owing 
to the oxygenation of the fibrous tissue. 
I ought here to observe, that when a thin vegetable substance is immersed in 
non-aeriated water, the latter quickly dissolves the air contained in the pneuma¬ 
tic organs of this vegetable substance, and takes the place of this air, so that 
there is no longer any oxygen in this vegetable matter. 
Experience justified my anticipations. The nerve of a corolla of Mirabilis , 
immersed in non-aeriated water, took and always retained its incurvation of 
waking. An expanded flower which, plunged entirely in aerated water, adopted 
after several hours the dormant state, and did not attain this condition in non- 
aeriated water, always retained its expanded or waking state. 
