124 CULTURE OF PLANTS. 



It is in consequence of this knowledge of the 

 limits that we are able to cultivate the plants and 

 the animals, and turn all the productions and 

 agencies in nature to our purposes. It is thus 

 that men, by means of the observations and dis- 

 coveries of successive generations, and the appli- 

 cations of those discoveries in such a manner as 

 to make each one an improvement on the one be- 

 fore it, have been able to cultivate the cereal 

 grasses into the wheat and barley which are now 

 the bread and the drink of so many millions. In 

 the same manner, by cultivating the apple, the 

 pear, the peach, the plum, and countless other 

 fruits, we have been able to turn an operation of 

 nature, the natural purpose of which was subser- 

 vient to the maturing of the seed of a plant, so 

 much from the natural purpose of the plant and 

 to our own purpose, that the ripening of the seed 

 is actually secondary to the growing of a repast 

 for us. In all nature, the application of similar 

 observations has produced corresponding results ; 

 and in some we have destroyed the purpose of 

 nature altogether, and made the plant wholly our 

 own and for our own use, in its living state as 

 well as when it is matured and fit for our purpose. 

 Many double flowers, and the dahlia in an espe- 

 cial manner, which, in their natural state, had 

 only one row of petals, have been so much con- 

 verted into petals by skilful culture, and the size 

 and beauty of these have been so much increased 

 along with their number, that the flower has 

 really ceased to be a flower, in the natural sense 

 of the word, though it has thereby become one 

 of the brightest ornaments of our gardens. There 

 are cases in which we have carried the matter 



