36 FLOWEKS. 



For this reason while leaf-buds can be used 

 for the purpose of propagation, flower-buds 

 cannot usually be so employed. 



Being stunted branches, their position on the 

 stem is the same as that of developed branches. 

 And as there is in all plants a veiy great 

 difference in the development of leaf-buds, 

 some growing readily into branches, others 

 only unfolding their leaves without elongating, 

 and many remaining altogether dormant, it 

 follows that flower-buds may form upon plants 

 of whatever age and in whatever state. 



But to produce a general formation of flow- 

 er-buds it is necessary that there should be 

 some general predisposing constitutional cause 

 independent of accidental circumstances. 



This predisposing cause is the accumulation 

 of sap and of secreted matter, as has been be- 

 fore explained. 



Therefore whatever tends to retard the free 

 flow of sap, and causes it to accumulate, will 

 cause the production of flower-buds, or fertility. 

 And on the other hand, whatever tends to 

 produce excessive vigor causes the rapid mo- 

 tion and dispersion of sap, or prevents its elab- 

 oration and causes sterility or want of flower- 

 buds. 



