546 



PHYSICAL GEOGRAPHY. 



CHAPTER XVII. 



GEOGRAPHICAL DISTRIBUTION OF PLANTS 



AVING reviewed the arrangements and pheno- 

 mena of inanimate nature, we proceed to con- 

 sider the globe as the habitation of innumerable 

 organised beings, beginning with the first de- 

 partment of the scale of living existence, the 

 diversified vegetable forms which clothe the 

 surface of the earth, adorn its scenery, and con- . 

 tribute to the sustenance of its animal and 

 human races. The productions of the vegetable 

 kingdom are among the most useful and in- 

 teresting objects we contemplate. They are 

 associated with the earliest and some of the 

 purest pleasures of mankind; for everyone will 

 vividly recollect the delight experienced in his 

 childhood by the appearance of the harbingers 

 of the vernal season the flowers of the snow- 

 drop, crocus, primrose, and violet, peeping up 

 above the greensward, or from the hedgerows, proclaiming, in an obvious and impressive 

 manner, "Lo, the winter is past, the rain is over and gone, the flowers appear upon 

 the earth, the time of the singing of birds is come." The cultivated flora of the 

 garden, and the wild flora of the field, are among our first and best instructors, conveying, 

 by their external configuration, lessons of purity and of grace to the mind in the age of 

 its awakening susceptibilities. This is a moral and intellectual discipline, silent and 

 unostentatious in its process, but of great importance in its effect as a source of valuable 

 directive influence to the thoughts and feelings. But to man, in mature life, the larger 

 plants and timber trees are essential. His existence and civilisation depend upon them. 

 They furnish, with unbounded prodigality, the food which satiates his hunger and 

 gratifies his taste ; supply many of the medicines that allay his sickness ; afford him 

 materials for an habitation ; yield the means of transporting himself and his property 

 across the land, and of accomplishing the passage of the ocean ; besides being the chief 

 ornament of his walks during the period of their growth. 



It belongs to Botany, Physiology, and Agricultural Chemistry, to investigate the 

 structure of plants ; to unfold the riches of the vegetable kingdom with its different 

 organisations, and the means by which their development and fructification are secured. 

 The department of the phj^sical geographer is simply to notice the general disposition 

 of the vegetable tribes, and the circumstances which seem to regulate their distribution. 



We have no more striking evidence of contrivance than in the wide dispersion of vege- 

 table life, and in the different conditions under which it exists, at the extremes of terrestrial 

 elevation and depression, of cold and heat, of light and shade, of solidity and solution. 

 Forests of beech wave in the Himalaya at a greater height than that reached by the Fin- 

 sterhorn of the Alps, or more than fourteen thousand feet ; and there also shrubs flourish 

 upon sites which are above the altitude of the hoary -headed Mont Blanc, the monarch of 



