SELECTING AND IMPROVING PLANTS IN CULTURE. 



dental variations, and cross-breeding. " Nature," Mr. Knight observes, 

 u has given to man the means of acquiring those tilings which constitute the 

 comforts and luxuries of civilised life, though not the things themselves ; it 

 has placed the raw material within its reach, but has left the preparation 

 and improvement of it to his own skill and industry. Every plant and 

 animal adapted to his service is made susceptible of endless changes, and as 

 far as relates to his use, of almost endless improvement. Variation is the 

 constant attendant on cultivation, both in the animal and vegetable world ; 

 and in each the offspring are constantly seen, in a greater or less degree, to 

 inherit the character of the parents from which they spring." (Knight's 

 Physiological Papers, c. p. 172.) 



862. Cultivation, then, is the first step in the progress of improving vege - 

 tables. It is almost needless to state that this consists in furnishing a plant 

 with a more favourable soil and climate than it had in a wild state ; supply- 

 ing food by manure to as great an extent as is consistent with health and 

 vigour ; allowing an ample space for its branches and leaves to expand and 

 expose themselves to the action of the sun and the air ; guarding the plant 

 from external injuries, by the peculiar kind of shelter and protection which 

 it may require, according as the object may be the improvement of the 

 entire plant, of its foliage only, of its flowers, or of its fruit. All cultivation 

 is founded on the principle that the constitution and qualities of plants are 

 susceptible of being influenced by the quantity and quality of the food with 

 which they are furnished, and that the constitution and qualities so formed 

 can be communicated to their offspring. The seeds of plants abundantly 

 supplied with food, and growing in a favourable climate, will produce plants 

 of luxuriant foliage, and larger than usual in all their parts ; while the con- 

 trary will be the case with seeds produced by plants grown in a meagre soil, 

 and in an unfavourable climate. Seeds produced in a hot climate will pro- 

 duce plants better adapted for that climate than seeds from a climate that is 

 cold, and the contrary ; and hence also the seeds of plants grown in a poor 

 soil and ungenial climate will succeed better in that soil and climate than 

 plants raised from seeds produced under more favourable circumstances. 

 Hence, in improving plants by cultivation, the experiments ought to be made 

 in the soil and climate for which they are intended. " No experienced 

 gardener," Mr. Knight observes, " can be ignorant that every species of fruit 

 acquires its greatest state of perfection in some peculiar soils and situations, 

 and under some peculiar mode of culture. The selection of a proper soil and 

 situation must therefore be the first object of the improver's pursuit ; and 

 nothing should be neglected which can add to the size, or improve the fla- 

 vour, of the fruit from which it is intended to propagate. Due attention to 

 these points will in almost all cases be found to comprehend all that is neces- 

 sary to insure the introduction of new varieties of fruit, of equal merit with 

 those from which they spring ; but the improver, who has to adapt his pro- 

 ductions to the cold and unsteady climate of Britain, has still many difficulties 

 to contend with : he has to combine hardiness, energy of character, and early 

 maturity, with the improvements of high cultivation. Nature has, how- 

 ever, in some measure pointed out the path he is to pursue ; and if it be 

 followed with patience and industry, no obstacles will be found which may 

 not be either removed or passed over. If two plants of the vine, or other 

 tree of similar habits, or even if obtained from cuttings of the same tree, 

 were placed to vegetate during several successive seasons in very different 



