CHAPTER I 

 INTRODUCTION 



1. Plant propagation is the multiplication or increase 

 in number of plants in the perpetuation of the species. 

 As applied by man, it includes knowledge of the proper 

 time, place and manner in which best results may be 

 secured. Fundamentally it is based upon (a) certain 

 natural laws or principles which constitute the science, 

 and (b) certain methods of manipulation which con- 

 stitute the art of the processes as a whole. 



2. Art and science contrasted. Art is merely the 

 knowledge of methods without reference to reasons 

 whereby results may be secured. It therefore implies 

 skill gained through practice. Science deals with the 

 underlying reasons for certain forms of procedure, and 

 the conditions which affect the process without consid- 

 ering the skill involved in manipulation. 



To illustrate : A workman in a nursery (Fig. 110) may easily 

 transplant 4,000 potted dahlia plants in a day of 10 hours without 

 knowing anything specific of the underlying principles; whereas, 

 the proprietor may know the principles and give proper orders for 

 their application without being able to transplant half as many plants 

 in the same time, yet he may be a master workman because of his 

 knowledge of both the art and the science. The art is best acquired 

 by following the example of a skilled workman ; the science best 

 from books and instructors. 



3. Natural and artificial methods. All methods em- 

 ployed by man are adaptations or improvements upon 

 natural methods, instances of the application of which 

 may be found in nature. For this reason they should 

 hardly be called artificial, though they are often so termed. 



4. Natural methods of propagation differ in the three 

 general classes of plants. Annuals and biennials all 

 propagate themselves by seeds, of which they usually pro- 

 duce an abundance. They are not propagated artificially 



