Propagation by Grafting. 



209 



the stem and roots upon their leaves, a fact often turned 

 to account in propagating these plants. Well -matured 

 leaves, with the principal nerves cut across on the under 

 side, are held in close contact with the surface of the 

 propagating bed by pegging or by light weights, or the 

 leaf may be cut into pieces, which may be placed in the 

 propagating bed and treated as ordinary green cuttings 

 (378). 



The leaves of the bryophyllum form rootlets and buds 

 from the notches on their borders wherever these chance 

 to come in contact with a moist medium. 



FIG. 103. Leaf of begonia on surface of propagating bed, forming 

 young plants. (After Bailey). 



b Propagation by Grafting. 



383. Grafting consists in placing together two portions 

 of a plant or of different plants, containing living cambium 

 (69) in such a way that their cambium parts are main- 

 tained in intimate contact. If the operation is success- 

 ful, growth will unite the two parts (70), and plant 

 processes will go on much as if the parts had never been 

 separated. The union usually takes place most rapidly 

 when the cambium cells are in the state of most rapid 

 division, i. e., when growth is most vigorous. 



