ON THINNING PLANTATIONS. 83 
the trees gradually as they get too close or too high for their 
girth. Planted pines are not commonly pruned, that being 
considered the worst mode of treatment. Many proprietors 
of late have given over thinning; but the woods are much 
hurt by being too much confined: a good tree can scarcely 
be seen, except near the outside, or where a road opens up 
and admits air. I am clearly of opinion that we shall not 
have good pine plantations until they are produced from the 
seeds of the native Highland forests, which are more healthy 
and permanent than the kind commonly cultivated’” 9th 
September 1837, Loudon adds, “The Earl of Aberdeen ; 
Macpherson Grant of Ballindalloch; Mr. George Saunders, 
gardener and forester to the Duke of Richmond at Gordon 
Castle; Mr. Roy, nurseryman, Aberdeen ; and other proprie- 
tors and gardeners of the north, have sent us answers to all 
our queries on the subject of thinning and pruning, which 
correspond with those given above by Mr. Grigor.” 
The natural provisions to prevent pines from rising close 
to one another, and of equal strength in the indigenous 
state, are very marked and interesting. The seeds on being 
shed are provided with wings adapted to carry and spread 
them throughout a wide district. They are never shed but 
in a warm and dry day, and as soon as the seed receives the 
slightest moisture it separates from the wing and travels no 
farther. Of such as fall into the soil a small proportion im- 
mediately vegetate; those that do not reach the soil, but are 
retained on the surface vegetation, may be picked up by birds, 
or are washed into the ground by the influence of the weather, 
and vegetate during some succeeding spring, for, under certain 
circumstances, the seeds of Scotch fir retain their vitality for 
several years even after they are separated from the cone. 
This is ascertained from seedlings appearing of various ages, 
years after being sown on moorland where no plants or seeds 
had previously existed. The diversity of situation also pro- 
duces a great difference in the strength and size of the plants; 
but even in the best prepared nursery-bed, where the seeds 
are all sown at the same time, and vegetate together, the 
