On the Physiology of Vegelalles, 181 



botlj air and water at times would almost become stagnate if it 

 were not for the spiral wire in the leaves. But so beautifully has 

 Nature contrived her laws, that the very moisture of the water, by 

 causing constant motion in the leaves, gives also increased mo- 

 tion to the water, and that water additional freshness to the airj 

 while the deep valleys, which have (jiiatUities of aquatic plants, 

 want (more thoroughly than any other) to have the oxygen 

 mixed with all other gases, to purify the atmosphere. How ex- 

 quisite then is this continual interchange of benefits ! — how de- 

 lightful then the discovery, " that not onlv the quantity of oxy- 

 gen is doubled in tliose vegetables found in low grounds, but the 

 spiral wire is also increased in an equal degree !" Thus botanic 

 physiology perfectly agrees with atmospheric chemistry, to en- 

 force the ivclfare and establish the happiness of each animal 

 that lives and brcatlies ; and not only of those wliose scent and 

 wholesome breathing is thus secured; but of those inanimate 

 beings who receive health and nutriment froin the very sjjoiled 

 air that is thus drawn off, and imbibed by them for their benefit. 

 Hydrogen and fixed air being in small degrees serviceable to 

 plants in genera!, though they will not grow in that air alone, 

 their absorption is of the utmost use to man and animals. Thus, 

 if the spiral was not the muscle of the plant, how could all thi.<i 

 be brought about? — how could the leaves be moved in stagnate 

 ^ituations ? — how could the oxygen get thoroughly mixed in the 

 higher regions? It would remain under the trees, to do harm to 

 the vegetable world; and so far from curing the bad vapours ia 

 low morasses, they would i)e left in their putrid state, to give 

 death to those who entered the valley. As the moist winds act 

 on the leaf of the poplars, so do they also on the corolla of 

 flowers, turning tiie back of tiie antirrhimim and pea-flower to 

 defend the pollen from the moist winds. How exquisitely sen- 

 sible are t!ie n)uscles of the plant! If a moist wind blows, they 

 will lengthen more and more, till they have lost all the twist of 

 their spiral wire: — if a dry north or east wind is felt, the muscle 

 will contract to half its loiislh. If there is no nuiscular con- 

 traction, wiiat makes the mulnu flower in certain dry winds push 

 off the whole of its corolla, by contracting the calyx to such a 

 degree as absolutely to pinch off the petals altogether? I have 

 often seen above twenty flowers thus iorced off, one after the 

 other, in an over-dry season. Those who do not look on the 

 jpiral wires as the muscle of the plant, but as sap-vessels, 

 should show IIS how a flower is o))eiied and shut ; how tiie ten- 

 drils tuist, both uit/iin and at the exterior of the flower ; how 

 those tendrils twisl, that cover the whole swjuce of a plant in 

 the way of hairs; — but particularly how the wood warps. They 

 M 3 proceed 



