FLOWERS. 37 



Transplantation with a partial destruction of 

 roots, age, or high temperature accompanied 

 by a dry atmosphere, training obliquely or in 

 an inverted direction, a constant destruction of 

 the extremities of young growing branches, will 

 all cause an accumulation of sap, and secre- 

 tions ; and consequently all such circumstances 

 are favorable to the production of flower-buds. 



But a richly manured soil, high temperature, 

 with great atmospheric humidity, or an uninter- 

 rupted flow of sap, are all causes of excessive 

 vigor, and are consequenfly unfavorable to the 

 production of flower-buds. 



There is a tendency in many flowers to en- 

 large, to alter their colors, or to change their 

 appearance by a transformation and multiplica- 

 tion of their parts, whenever they have been 

 raised from seeds for several generations, or 

 domesticated. 



The causes of this tendency are probably 

 various, but being entirely unknown, no cer- 

 tain rules for the production of varieties in 

 flowers can be laid down, except by the aid of 

 hybridising. 



Tt often happens that a single branch pro- 

 duces flowers different from those produced on 

 4 



