10'2 EXTRACTS FROM FOREIGN PERIODICALS. 



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 whicb 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 sleep, 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 sjTup. 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 Avould 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 an}' 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. 



