32 



often produce suckers from their roots in the neighbour- 

 hood of the parent plant. Such growths can be separated 

 and developed into new individuals. In the case of Rasp- 

 berries indeed, this is a common method of propagating 

 the canes. 



Lastly, it has been found possible in the case of some 

 plants vvith somewhat fleshy leaves to cause thesie, or even 

 portions of a leaf, to produce adventitious buds. This is 

 the case with many Begonias, particularly those belonging 

 to large-leaved varieties. If the leaf is placed on damp 

 soil, the midrib having been cut in several places, new 

 plants may arise from each portion as with the stimulus 

 of warm temperature and moisture the leaf produces a 

 considerable growth of callus, from which adventitious 

 buds soon arise. The fleshy scales forming the bulbs of 

 most lilies are capable when separated from the parent 

 bulb of producing small adventitious buds from which 

 new plants can be grown, and this is a common method of 

 propagating the plants. 



Space prevents a detailed discussion of the processes of 

 bitddiJig and grafting, but from the botanical point of 

 view the processes may be regarded as a special case of 

 making cuttings in which the latter, instead of being 

 planted in soil, are inserted in the tissues of a nearly 

 related plant with which they become united by the 

 development of wound tissue or callus. No adventitious 

 roots are formed by the graft as the scion relies for its 

 supply of water entirely upon the roots of the stock. 



There has been much discussion as to whether, as a 

 result of grafting, there is any influence of the stock upon 

 the scion, or vice versa. A considerable amount of infor- 

 mation on this question has accumulated, but it is largely 

 of a negative character, and what positive evidence exists 

 is of a doubtful nature. 



