CrlifiMiNAiiUi'J. » 17 



any given locality, such as the qualities of the soil, the degree of moistui-e both of 

 the earth and skies, the inclination of surface, rocks, shades, and winds, the com- 

 bined action of which often becomes an exceedingly complicated matter. Now 

 to each of these innumerable combinations of circumstances, the Creator has 

 adapted the constitution of certain species of plants, so that each given locality 

 may be expected to produce its own appropriate kinds. But since some species 

 are also endowed with the power of accommodating themselves to a wde range 

 of circumstances, these are found more extensively diffused, while otliers, mthout 

 this power, are comparatively rare. 



15. V^etation is susceptible of important changes by culti- 

 vation. iJMany plants are improved, in every desirable quality, 

 by accommodating themselves to the conditions of soils enriched 

 and enhvened by art. Examples are seen in almost every cid- 

 tivated species,^ 



16. The cabbage,; in its wild state, is a slender, branching herb, with no appear- 

 ance of a head.,; The potatoe, in its native -vvilds of tropical America, is a rank, 

 mnning vine, with scarcely a tuber upon its roots. All t!ie rich and delicate 

 varieties of the apple have sprung, by artilicial means, from an austei-e forest- 

 fi-uit. The numerous and splendid vaiieties of the Dahlia are the descendants 

 of a coarse Mexican plant, -ivith an ordinary yellow flower, of a single cuxle of 

 colored leaves. The tulip and the geranium afford similar examples. 



17. Changes, not only in the qualities of vegetatioir, are ef- 

 fected by culture, but also in the species themselves, tlirough the 

 substitution of the useful or the ornamental for the native pro- 

 ducts of the soil. Thus, in agricultural districts, almost the 

 w xiole face of natiu-e is transformed, by human skill and industiy, 

 from the wilderness to the fruitful field. 



a. Hence it appears diat there is scarcely a spot on earth which is not caused, 

 by the quickening energy of the Creator, to teem witli vegetable existence, in some 

 of its numberless fonns, while his goodness is conspicuous in rendering those 

 bibes wliich are most subservient to the wants of man capable of the Avidest dif- 

 fusion. 



