210 PLANT LIFE 



a circumstance of which advantage is taken 

 in the propagation of valued species and 

 varieties. Everybody knows how simple it 

 often is to increase a plant by cuttings. 

 Sometimes cuttings of roots will grow just 

 as easily as those of stems, and even the 

 leaves of some plants may be used with almost 

 certain chances of success. Begonias, for 

 example, and certain other greenhouse plants, 

 are generally propagated in this way. 



Again, in the operations of budding and 

 grafting, we see how the. process of cell division 

 and multiplication is followed by cohesion; 

 the bud or the graft "takes," becomes 

 united with the tissues of the stock. Instead 

 of the bud or cutting being planted in the 

 soil, it is here planted on to another organism. 

 And, in passing, we may note that the graft 

 produces no roots, as it would have done if 

 planted in the soil. The internal stimulus 

 which might have led to root production is 

 absent, inhibited, perhaps, by the nutrition 

 that is plentifully poured in from the tissues 

 of the plant on which the bud or graft is 

 growing. 



All the various examples of multiplication 

 and propagation to which allusion has been 

 made in this chapter are instances of what 

 may best be called vegetative reproduction or 

 propagation, and they are seen to be intimately 

 related with the functions of growth and 

 nutrition. They represent various methods 

 of dividing up the individual, and the liberated 



