THE TEEATMENT OF BOOTS 85 



(b.) A Root Systemfrom which only the Delicate Boots have 

 ieen Removed. 



In discussing the treatment of roots in transplanting, we 

 liave purposely distinguished those cases in which the older 

 roots have been removed from those in which the younger and 

 niore delicate roots only have been injured, for the methods of 

 healing are different in the two cases. The younger a root, 

 the more easily will it heal, and the more copiously and more 

 rapidly will it produce adventitious roots. This can be very 

 readily seen in trees which are taken up again a few years 

 after transplantation. Around the wound produced by the 

 cutting of a large root, there will be seen a ring of delicate 

 adventitious roots, some of which will have become stronger 

 roots. The adventitious roots, produced from younger struc- 

 tures, are perhaps not equally numerous, but their dimensions 

 are so perfect that they are often not to be distinguished from 

 the undamaged roots of the same age. 



A root system, therefore, which has been pruned back con- 

 siderably will take a longer time to produce a sufficient 

 absorptive system, the stem therefore will have only a small 

 supply of water, and will require a treatment tending to re- 

 duce the transpiration for a longer period than a plant in 

 which the delicate roots only have been cut. 



It is therefore most advantageous in pruning roots to avoid 

 Jf possible the cutting of the older roots. 



(c.) The Treatment of Roots in Be- Potting. 



The necessity for re-potting occurs either when the root 

 system is diseased or when the soil has become exhausted by 

 very active growth. 



In the case of diseased roots, the above-mentioned precau- 

 tions with regard to the upper portions of the plant should be 

 remembered. One is forced on these occasions to cut back 

 the roots to the entirely healthy portions, and therefore to cut 

 back to the old wood; and this must not be done sparingly. 

 iFor if the smallest decayed portions are left, there is great 



