MANAGEMENT OP CUTTINGS, &c. 147 



plants, to keep all the sap in the plant until 

 new roots are formed to supply it with more 

 and hence the reason of putting cuttings under 

 a glass, which excludes the air ; but, whenever 

 the roots are formed, the glasses should be 

 removed, as, by excluding the air, little sap is 

 exhausted, the roots are not called on to supply 

 much, and therefore (Jo not grow; and the 

 plant dwindles away. 



Try this, and be convinced; one failure, with 

 the cause of it found out, will often teach more 

 than twenty successful experiments. Adversity 

 and misfortune, in all things, are good, though 

 hard mistresses. 



If you have any wish to raise bulbous roots 

 from seeds, these should now be sown in pots 

 or boxes ; but it will be so long before these 

 seedlings come to perfection, even with great 

 experience and care, that I should advise you 



