PRINCIPLES INVOLVED 113 



pleted the year's growth and passed into a quiescent stage. 

 If the plant is in active growth the cuttings would be 

 semi-dormant. Cuttings taken from the young shoots 

 of the current year's growth or from the sub-tropical fruits, 

 which never pass into a complete dormant stage, belong to 

 this class. Then there is a third type of cutting made from 

 plants which have only soft or succulent growths. Such 

 plants as geraniums, cacti and many other flowering kinds 

 belong to this type. Vegetative propagation from such 

 plants would be called Softwood Cuttings. 



Principles Involved. The different classes of cuttings 

 are widely variable in their physiological and chemical 

 activities and should therefore be treated differently in 

 the "processes of propagation. Plant Physiologists tell 

 us that every part of the individual plant has in it, poten- 

 tially at least, all the essentials necessary for the production 

 of the mature individual. As the cell is the unit of the plant 

 so in that cell is located everything necessary to develop 

 the future buds, roots, leaves and flowers. That some cells 

 possess this quality to a greater degree than others is 

 amply proven by the ease or difficulty with which differ- 

 ent cuttings may be used for propagation. 



The part of the plant tissue possessing the greater value 

 in propagation is closely associated with the cambium 

 layer. In fact the same tissue which makes possible 

 budding and grafting produces the new buds, roots and 

 leaves where cuttings are used. The cambium layer, 

 then, containing the primary or unorganized tissue is 

 the important part. The stem and root cuttings of the 

 ordinary trees and shrubs have this tissue just beneath 



