210 PRINCIPLES OF GARDENING. [CH. VI. 



must be some tendency in the parent thus to sport, 

 otherwise the superfluity of food will not have the 

 desired influence. That abundance of nourishment 

 is necessary appears from the fact, that if the double- 

 daisy, or the double-narcissus be grown in a poor 

 soil they speedily produce none but single flowers, 

 yet, if they again be restored to a rich soil, they 

 may, with care, be made to produce an unnatural 

 profusion of petals. Mr. D. Beaton's estimate of a 

 double flower is original. He says that cultivation 

 having enlarged all the parts of a plant, the consti- 

 tutional vigour thus obtained is transferred to the 

 next generation, and to some of the seedlings, in a 

 measure, even greater than that possessed by the 

 parent. Extraordinary supplies of nourishment, 

 under favourable circumstances, invigorate still fur- 

 ther the improved race, and so on through many 

 generations. During this time cultivation produces 

 the very opposite of double-flowers, and Mr. Beaton 

 thinks it would continue to do so if it were possible 

 to keep up every member of each generation to the 

 same degree of health and vigour; but accidents 

 and diseases overtake some of the plants, and double- 

 flowers are the produce from these decrepits. Cul- 

 tivation, according to this idea, is only indirectly 

 the cause of double-flowers, and these a retrograde 

 step from a liigh state of developement. 



