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LOUDON'S ARBORETUM ET FRUTICETUM BRITANNICUM. 
by ridiculing every hypothesis, however plausible from analogy or partial experi- 
ment, if not absolutely established. On the contrary, these volumes abound in 
novel hints of the most satisfactory nature ; and the only obstacle to their success 
seems to us to be the reluctance of many to attempt their proper effectuation. Of 
these hints we may hereafter give a few examples. The topic of this kind on 
which we wish especially to dwell, is the strong countenance throughout afforded 
to the theory of acclimatation. That hundreds, indeed thousands of exotic 
plants have been thoroughly acclimatized in this country, the examination of our 
catalogues of indigenous species, and a simultaneous tour through our gardens and 
woods, will speedily demonstrate. Besides, those conversant with the introduction 
and subsequent history of many Chinese, Japanese, North Indian, and other plants, 
well know that, making allowances for their injudicious treatment with regard to 
temperature at the period of their importation, they have gained at least some 
degree of hardihood by exposure to our less genial and very variable atmosphere. 
There can be no doubt that the benevolent Author of being has placed every 
living object in the climate most suitable to its natural wants. Nevertheless, it is 
quite as certain that the peculiar constitutions of vegetable bodies are capable of 
being extensively modified by a long continuance in certain circumstances, to 
which, if not gradually accustomed, they would never conform themselves. Life, 
wherever it exists, always evinces a remarkable tenacity of continuance ; and thus 
we see plants of a strong organization, struggling so effectually amidst slightly 
inimical conditions, through the energy of the vital principle, as ultimately to 
become perfectly habituated to them, and to bear their occurrence without injury. 
It may be that the ordinary duration of such specimens is thereby a little shortened ; 
but if the end for which they were destined — that of flourishing in the open ground 
for a lengthened period — is duly fulfilled, the gratification of the cultivator is a 
necessary consequence, and their offspring are better able to fill the places vacated 
by their decay, than any specimens taken from a more congenial position. 
This leads us to the remark that seeds ripened or germinated in heat will never 
produce such hardy plants as those matured and vegetated in the open air. And 
the position will be at once obvious on a close observation of the actual state of 
plants so raised. Seeds which reach maturity in a high temperature, must have 
their infant organization of that increased induration of texture and tenuity of 
cellular structure, which heat invariably engenders. Such a rudimentary state 
demands proportionate stimuli for elaboration. So that, when development is 
excited in a lower temperature, it will be sluggish, imperfect, and too refined and 
delicate to advance healthily under the obstructions which cold presents ; in 
other words, it will be far more susceptible of damage. If heat be further 
employed, all these conditions will be sensibly aggravated. 
To advert to specimens germinated from hardy seeds in an artificial tempera- 
ture, their stems and branches are essentially precocious and debilitated ; their 
pores open, their vessels attenuated, their juices unusually limpid ; they cannot 
acquire, in proportion to their progress, that solidity, thickness, and hardness of 
