Propagation by Detached Parts. 199 



stored for preservation in a cool, moderately dry place, 

 that is free from frost. They retain their vitality but 

 a single year. 



In the methods of propagation thus far considered, 

 with the sole exception of layering (349), advantage 

 has been taken of a natural mode of plant multiplica- 

 tion. The skill of the cultivator, however much it may 

 assist the processes, is not necessary to their success, 

 since wild plants habitually increase by the same meth- 

 ods. We will now consider a method which is less often 

 illustrated in nature, and in which the skill and care of 

 the cultivator are, as a rule, essential to its accomplish- 

 ment, viz: 



b Propagation by sections of the plant. 



The various methods of propagation in this division 

 are alike in the fact that a detached part of the parent 

 plant, containing living protoplasm, is placed for a time 

 under specially favorable conditions, in virtue of which 

 the part is enabled not only to live, but to perform its 

 functions and reproduce the needed organs ; or if a cion 

 (386), to unite by growth to the part with which it is 

 placed in contact. 



357. In propagation by sections of the plant we must, 

 of necessity, wound the plant tissues in securing the 

 parts for propagation. Since it is always desirable that 

 the wound should heal promptly (72), it is important 

 that the cutting tools used should liave sharp and 

 smooth edges. 



As here considered, propagation by sections of the 

 plant includes two methods, differing materially in 



