RELATION BETWEEN CLIMATE AND VEGETATION. 203 



elucidation of scientific deductions — I think we shall see that tlie 

 practice of early afternoon closing is detrimental to the proper 

 and perfect development of vegetable life. It may, and does, 

 induce elongation, but tliat is no gain, as regards actual bulk of 

 organized matter in tiie plant. It is essentially a species of wire- 

 drawing, in wiiich the same matter is lengthened and made to 

 assume a more extended bulk without such actually being the 

 case, and at the same time the original is weakened : it gives, as 

 it \vere, an impulse to growth at a season ^hen a degree of 

 repose and solidification of pre-existing tissues should be going on : 

 it deranges the circle of organic phenomena, and consequentl}^ 

 depreciates the capabilities of tlie individual. For it must be 

 borne in mind that the tissues of a plant once advanced in the 

 scale of organization beyond the simple elementary form of cellular 

 tissue, can never retrograde : they may possibly remain stationary 

 or be imperfectly advanced, as is both the cause and effect of some 

 diseases ; but if that advanced condition has taken place vmder 

 unfavourable circumstances, the ill efi'ects of such must remain 

 indelibly fixed as a constitutional derangement, and as .such will 

 ever after influence the perfect development of tlie individual. 

 It appears to me more and more forcibly, with every successive 

 inquiry I make in the subject, that horticulture as a science must 

 be based upon physiological facts, and that physiology must 

 consent to descend in some degree from the elevated position it 

 assumes, and condescend to deduce the basis, the foundation of 

 its theory, from investigations of the simplest forms of vegetable 

 life. The whole series of phenomena constituting tlie origin and 

 maturity of some of the lower forms of plants are but the first 

 steps of organization in some higher in the scale ; but each is 

 perfect of its kind. And it is in its most simple form that we can 

 observe with advantage the phenomena of life. It is here we must 

 study the connection between the constitution of vegetables and 

 the external circumstances to which they may be exposed, and 

 the results produced in subsequent stages of development. A 

 physiology based upon such principles can alone be of real worth 

 in its practical application to horticultural purposes. 



XXII. — Contributions to a History of the Relation between 

 Climate and Vegetation in various parts of the Globe. 



No. 9. — Climate of Australind, Wester7i Australia. An 

 Extract from a Letter to the Vice-Secretary from M. 

 "Waller Clifton, E.sq., dated 25 September, 1848. 



When I came out in charge of the expedition to found this 

 settlement (the success of which was almost at once destroyed 

 by the proceedings and failure at home of the Western Australia 



