HIGHWOODS, COPSES, ETC. 279 
satisfactory trees, and to underplant those re- 
maining, or else gradually to clear off the whole 
of the wood and form a new crop, either by 
means of natural regeneration or by sowing and 
planting. Again, many young coniferous crops 
formed during the last twenty-five to thirty-five 
years have been planted at distances varying from 
4 feet by 4 feet to 6 feet by 6 feet, with the conse- 
quence that some of these latter, of pine especially, 
are only now beginning to form close canopy for 
woods of their class, and commencing to clean 
themselves of their lower branchlets. They are 
often now just at the stage when they are likely 
to be very prejudicially affected as to their ulti- 
mate value as a crop if the past arboricultural 
method of heavy thinning be still followed. The 
best treatment for such plantations lies in the 
careful retention of the close cover now at length 
attained, and in the restriction of thinnings to 
the mere removal of almost suppressed or of 
badly-diseased poles, and the cutting off of dead 
branches and snags. Canopy being adequately 
maintained, such woods can be thinned every 
four or five years, yielding good returns wher- 
ever there is a fair market for large poles, till 
