280 APPLICATION OF PRINCIPLES. 



And yet the rationale is simple enough, if we do not 

 labour to render it confused by imaginary refine- 

 ments. 



When a plant is taken out of the ground for trans- 

 planting, its roots are necessarily more or less injured 

 in the process, and consequently it is less able to sup- 

 port the stem than it was before the mutilation took 

 place ; its loss of this power will also be in proportion 

 to the extent of the mutilation, which may be carried 

 so far as to amount to destruction. 



But the importance of their roots to plants is not 

 alike at all seasons ; in the summer, when there is the 

 greatest demand upon them in consequence of the 

 perspiration of the - foliage (70, &c), they are most 

 essential ; in winter, when the leaves have fallen, 

 they are comparatively unimportant, as is evident 

 from a very common case. Let a limb of a tree be 

 felled in full leaf in June ; its foliage will presently 

 wither, ihe bark will shrivel and dry up, and the 

 whole will speedily perish ; but, if a similar limb is 

 lopped in November, when its foliage has naturally 

 fallen off, it will exhibit no sign of death during win- 

 ter, nor till the return of spring, when it may make a 

 dying effort to recover ; but the means it takes to do 

 so, namely, the emission of leaves, only accelerates 

 its end. 



These two propositions really include all the most 



way apply to Mr. Macnab's Hints on the Planting and General 

 Treatment of Hardy Evergreens in the Climate of Scotland; an 

 excellent treatise, which it is impossible to recommend too strongly 

 to the attention of the planter. 



