xii INTRODUCTION. 



rocks. The growth in each of the three kingdoms of nature Is, however, a different 

 operation, acting upon different principles, and producing different results ; and, for that 

 reason, growth can form no part of the general definition of any of the kingdoms of nature; 

 though the particular mode of growth is an important character. 



A vegetable is, like an animal, a whole, and cannot be divided without mutilation ; 

 though the vegetables which admit of being multiplied by dividing the existing ones are 

 much more numerous than the animals that can be so multiplied. The production, growth, 

 and general functions of vegetables, form the subject of VKGKTABLE PHYSIOLOGY. 



Though some vegetables float in the water, and others hang suspended in the air, yet 

 their general habit is to be rooted in the ground; and no vegetable, whether rooted or not. 

 changes its place, unless removed by some external cause. But this negative quality of 

 the want of locomotion cannot be made part of an exact general definition of vegetables, 

 any more than the active quality of growing ; for it is a general property of matter, 

 whether organised or not ; and it is also a property of some species of animals. 



But though this want of locomotion cannot enter into the definition of vegetables, it is 

 a very important point in natural history, and renders the vegetable tribes far better indi- 

 cations of climates .and seasons than the animals are. All animals can, to a certain extent, 

 avoid circumstances and occurrences which are disagreeable to their nature; and though 

 plants can do the same in a very slight degree, more especially in those parts of their organisa- 

 tion which are the most delicate, and, as one would say, the most immediately alive, yet it 

 may in general be said that the vegetable must stand exposed and abide whatever happens. 

 No doubt the power of endurance in them is much greater than it is in animals ; and as 

 we have already seen that those animals which have the principle of life the least developed, 

 or have their organisation the most simple, are the most capable of enduring ; so we find 

 that vegetables are generally more capable of enduring than animals, and that the more 

 simple the organisation of the vegetable, the more enduring it will be. By endurance 

 is not meant the resistance of external causes and circumstances generally ; but rather the 

 obedience to these, or the resistance of destruction, which is really a yielding to the course 

 and operations of nature. 



The circumstances now mentioned give a very peculiar interest to the natural history 

 of vegetables. No plant, taken simply in itself, is perhaps so interesting as some animals, 

 as it wants the charms of perceptible activity and affection ; but it is in vegetables far more 

 than in animals that we trace the variations of different regions of the earth, and those of 

 the same region in the "different seasons of the year. All that we can perceive of the action 

 of the sun, the atmosphere, and atmospheric humidity, upon the inorganic and dead matter of 

 the earth, is illuminating or darkening, heating or cooling, drying or moistening, softening OB 

 hardening, or, even in the extreme cases, mechanical division or chemical solution. Buff 

 vegetables bring into play the principle of growth (at least their own form of it) ; and the 

 operation of that principle, or, which amounts to the same thing, the operation of climate 

 or season upon it, evolves all those curious forms which every where compose the carpet or 

 clothing of the earth, where its mineral surface is not permanently too cold, too dry, or too 

 shifting, for allowing the principle to act. 



The natural history of the vegetable kingdom thus admits more readily and more dis- 

 tinctly of division into three parts than that of the animal kingdom. First, the descriptive 

 history of the species, singly, but in their classification ; and that constitutes the science of 

 BOTANY, a word which originally meant grass, the grasses being, in the pastoral times, 

 as they are still, the most important vegetables of temperate climates. Secondly, the 

 species of plants which are, generally speaking, best adapted to the different latitudes of the 

 globe, grow most abundantly and readily, and are most characteristic of the scenery there. 



