THE NATURAL REGENERATION OF WOODS. it 
sively. At the same time attention should be given to felling all 
trees which are provided with low-reaching branches, as these, 
owing to the excessive shade which they produce, are apt to act 
prejudicially on the young generation. If, however, such trees 
must be retained, in order to furnish the necessary seed, or for 
purposes of protection, then all their branches ought to be removed 
for 20 feet from the ground. 
The species of tree, kind of soil, climate, etc., must regulate the 
amount of shading which should be retained at this time ; or, what 
is the same thing, these considerations should decide the extent of 
the seed felling. In the case of shade-bearing trees, it is usually 
sufficient to bring the wood into such a state that the edges of the 
crowns of the trees are separated 3 to 9 feet from each other, which 
implies the removal during the advance and seed fellings of from 
a quarter to three quarters of the original number of trees. Light- 
demanding trees require at least twice this amount of thinning 
unless a subsequent felling can be made very soon after the seed 
year, in which case it is better not to fell too heavily at first for 
fear the seeding should not be successful or complete, when it may 
be necessary to supplement by utilising a second seed year. 
As a general rule, one should not make the wood too thin where 
the land is of the character which predisposes it to produce a strong 
growth of weeds, for the only way of keeping them in check is to 
retain a considerable amount of shade. Here, again, species must 
be taken into account, for the rate of development in youth varies 
greatly, some—for instance, the silver fir—growing very slowly 
when young, and consequently being lable to be choked by rank 
vegetation, while others, such as the larch, grow so rapidly as soon 
to be out of all danger from this cause. 
In frosty localities, or in the case of tender trees, more shading 
should be retained than under opposite conditions ; and the same 
is true where insects are numerous, or where the soil is very dry 
and apt to suffer from excessive drought. 
Should artificial assistance be necessary, the stage of the seed 
felling is the most suitable time to complete the preparation of the 
seed-bed. Ifthe advance fellings have been too heavy, or if severe 
gales have occurred, a considerable amount of ground vegetation 
may have found a footing. This must be got rid of, at least in 
part; but if not very plentiful, the disturbance of the surface 
occasioned by felling and dragging the trees is usually sufficient 
preparation. If the trees have been felled with their stools attached, 
