62 PLANTING. 



been previously undercut, they should now be shortened, 

 and any injured roots should be removed. Immedi- 

 ately this is done, immerse the roots and a few inches 

 of the stem in a puddle of clay and water, of such a 

 consistency that it will stick well to them. Whoever 

 has paid much attention to the structure and functions 

 of roots, and has observed that it is through the spon- 

 gioles at the ends of the slender fibres — and through 

 these alone — that the plant obtains its nourishment 

 from the soil, will hesitate before cutting back a single 

 root. The larger roots are covered with an epidermis 

 or skin, which in older trees becomes thickened into a 

 cortical integument like bark, and are quite destitute 

 of pores. 



" Though root- pruning is a custom ' more honoured 

 in the breach than the observance,' yet it will often 

 be necessary to prune back the head of a plant so as 

 to start it on its course with a fair chance of success. 

 This will be desirable when, from injury or otherwise, 

 its root-growth is greatly disproportioned to the size of 

 the head. To replant it in this state would be to start 

 it on its course too heavily handicapped, and sooner or 

 later it must succumb. By a judicious lightening of 

 the head, and thus adapting its requirements to the 

 power of the roots, the equilibrium may be restored, 

 and such shoots only will be produced as the roots 

 have power to support. The neglect of this precaution 

 is the reason why, in a new plantation, so many of the 

 trees shoot only from near the ground, or break out in 

 sprigs a little way up. But such pruning as is here 

 recommended requires great care and judgment, and 

 should only be intrusted to experienced hands. Be- 

 sides, as it can only be practised in the case of decidu- 



