Consider the lilies : an address delivered at the opening of the course of lectures in physiology in the Victoria University of Manchester / by William Stirling.

  • William Stirling
Date:
1910
Catalogue details

Licence: In copyright

Credit: Consider the lilies : an address delivered at the opening of the course of lectures in physiology in the Victoria University of Manchester / by William Stirling. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    lu HOOTS. Hresently 1 lio])e lo skow you sometkiug' about tke uuuvellous work of those organs of a plaut—the uooxs -which carry ou their work iu darkness—roots in Huskiu’s words, “ Cleaving the strength of rocks or junuing the tiauscieuce of the sand,” invisible, yet potent parts of the great earth veil. The roots—pushinl, penetrating, persistent explorers of the subterranean world--tiud part of tlieir fooil as they grow. Their work, Jiowever, is altruistic. 1 liey not only as it weie anc/iur the ])lant, but they absorb nater anil mineral salts, and send up sap tlirough the stem into the green li'aves. \\ e shall see that they perform iu addition many other useful functions. ■■ April sap to topmost tree, that shoots Aew buds to Heaven.” (“The Toresters.”) L^:A^•ES. Leaves—“ the feeders of the [ilant ’—are veritable organic Laboratories where most wonderful chemical Iransfoimations are idfected. For example, some relatividy simple compounds are broken up, the lesulling products are rearranged and many new complex chemical substances are foriiu'd. Fiom openings -tbe iikkariii.vi; cokes or stomata—on the surface of leaves—and there are myriads of them -water is given out as water va|)our—while from the air, carbonic acid iu a continuous stream, is taken in. In sunlight, gieen leaves give out oxygen. In sunlight and darkness alike, green plants give out car- bonic acid, as we do. the carbonic acid is the product of their lireathing or respiratory activity. In a WATKUV laboratory, inside the leaf, are formed sugars, starches, and other organic substances, so that at nightfall a leaf contains a store of nutriment—the produce of the labour of tin* day. Muring t/tirfcncss, the insoluble starcbes aie converted into siduble sugars, which are carried from the leaf to the stem and other parts of the plant where they are reiiuired—for the well-being of the plant itself—for growth, for developmt'ut, and for the formation of new wood or buds, or flowers, as the case may be. Xext morning, at sunrise, the daily task is begun, and con- tinued until nightfall. Each Leaf acts as a Hi ildek. and, as Ku.skin says, “ leads a life of endurance, effort, and various success, issuing in various beauty: and it connects itself with tbe whole jirevious edifice by one sustaining tbread, continuing its appointed piece of work all the way from top to root.”