188 PRINCIPLES 'OF PLANT CULTURE 



343. Propagation by division of the plant is used 

 when it is desired to reproduce the exact parental form, 

 as in fruit and the finer ornamental trees, many flower- 

 ing plants and the like ; in certain plants that are more 

 readily multiplied by division than by seeds, as mint and 

 many other perennial herbs; and in other plants that 

 rarely or never produce seed, as the horse-radish, sugar 

 cane, banana and so on. 



We have seen that a part of a plant, placed under 

 favorable conditions, is frequently capable of develop- 

 ing a complete plant (343). A section or cutting of the 

 stem, for example, that has no roots at the time it is cut 

 off, may be caused to form roots, and thus become a 

 complete plant. A cutting of a root may also put forth 

 a bud, which in turn may develop into a shoot, and form 

 leaves, flowers and fruit. Again, we have seen that 

 portions of cambium from different, nearly-related plants 

 may unite by growth (69), which enables us to change 

 undesirable sorts into valuable ones by grafting (383). 

 These and certain other methods of multiplying plants 

 come under propagation by division. 



In propagation by division, the presence of at least one 

 healthy growing point (66) in the part selected for the 

 propagation is generally essential to success and is always 

 helpful. 



The processes treated in this and the two succeeding 

 sections may be likened to surgical operations in medi- 

 cine. If plants are less highly organized and possess 

 less of sensibility than the higher animals, they are, 

 none the less, living beings. Violent operations, if nec- 

 essary, should always be performed with this truth in 

 mind. Needless injury and careless handling in the 

 treatment of plants are always to be avoided. 



