278 OUR FORESTS AND WOODLANDS 
jected to rational treatment from the very time 
of their formation onwards, because good pre- 
sent and future management is not of itself, in 
many cases, able to correct the mistakes of the 
past. Plantations made at wide distances, such 
as 6 feet by 6 feet for larch, pine, or spruce, 
though below normal density up to fifteen or 
twenty years of age, may, if simply left to grow 
as they like, become crowded at twenty to thirty 
years of age. In such cases the crowding would 
be solely due to excessive development of branches, 
and not to any excessive number of stems per 
acre. Errors of this sort can of course be re- 
medied to a certain extent by thinning. It is 
also true that thinning is not merely the best 
means—it is often, indeed, the only possible 
means—of tending timber crops; but the damage 
done to timber in Britain by injudicious thinning 
throughout the last hundred years might probably 
be moderately assessed at many millions of pounds 
sterling. 
In the case of many of the older woods the 
damage thus done has been so great that but 
little can now be suggested except to harvest the 
over-mature, the most branching, and the least 
