242 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY. 
to develop their diameter-growth more rapidly. The object now 
in view will be to lead the trees to the attainment of the desired 
diameter before the time for their removal arrives, while main- 
taining as many of them on the ground as is possible, consistently 
with the fulfilment of this allimportant condition. If it should 
appear that one such thinning will produce the desired effect, 
the crop may then be left until the time for felling arrives ; 
otherwise, an additional thinning (B) will be made 3 or 4 years 
later. But the degree of the thinning (A) should not be 
increased with the object of avoiding the necessity for the 
thinning (B), to which there is no objection; for all thinnings 
should be cautiously made, and the crop must at all times be 
kept as dense as is consistent with the attainment of the desired 
dimensions. Should it be found necessary to thin, on an aver- 
age, four times in each felling-area of 20 acres, then it would 
follow that, in addition to the fellings of the year, thinnings 
would be made annually in four other felling-areas, 7.e., over an 
area averaging 80 acres. 
Where larch forms part of the crop, it will receive special 
attention, with a view to retaining as many as possible of these 
trees to the end of the rotation. When the time for felling 
arrives, all larch trees which promise to stand and develop 
profitably during a second rotation will be spared; when 
removed at 80 years of age, they will form a valuable element 
in the yield. It is hoped that by introducing larch, scattered 
at comparatively wide intervals in a crop of evergreen trees, a 
considerable portion of them may escape the disease, which will, 
at any rate, not spread so easily as if the crop contained a larger 
proportion of this species. Dead side-branches of Scots fir and 
larch may be knocked off during dry summer weather or during 
frost; they will be of small size. For spruce, however, it will 
probably be necessary to use a saw. In either case, dead 
branches must always be removed flush with the stem or not 
at all. 
The mixture of Scots fir and spruce prevailing in the younger 
woods is one to be avoided in future. In nearly all crops thus 
constituted, the leading shoots of a large proportion of the spruce 
are now suffering severely from being rubbed by the upper side- 
branches of the Scots fir, which grow more rapidly in youth; 
and unless measures are at once taken to free the heads of the 
spruce, by lopping the side-branches of the Scots fir, the spruce 
