34 BULLETIN 1061, U. S. DEPARTMENT OF AGRICULTURE. 
examinations permit of the announcement without reserve that the 
limber of longleaf pine is in no way affected by the tapping for 
turpentine. It is further pointed out that in this statement the 
chemical as well as the mechanical properties are considered, and 
thus all doubt as to the comparative durability of timber from bled 
and unbled trees is eliminated. 
Preliminary studies of the effect of turpentining upon second- 
growth longleaf pine indicate, as a result, some check in the rate of 
growth for an indefinite period of perhaps two to four years fol- 
lowing operations, depending on the severity of the bleeding of the 
tree. Locally near the face, growth takes place rapidly on account 
of an apparent effort of the tree to heel the wound, making very 
favorable conditions of the wood for later working. Additional in- 
formation on this particular phase of growth is much needed. 
CUTTING. 
Thrifty, well-stocked stands of longleaf soon become overcrowded, 
and a great competition arises among the trees, the foliage seeking 
for light and the roots for soil moisture. This should be closely 
looked after by the owner. Longleaf does not readily thin itself 
by the natural dying-out process, but many of the smaller trees may 
live years in a practically dormant condition. The stronger trees 
gradually crowd and kill the weaker individuals. If such timber 
is left unthinned. big losses may be expected in the potential timber- 
producing power of the stand. 
With some kinds of trees and forests it is more profitable if the 
largest trees are cut and the smaller ones are allowed to grow and 
take the places of those that have been cut. This system, however, is 
not generally to be recommended for longleaf pine. The method of 
cutting believed to be most applicable to longleaf consists in thin- 
ning from the bottom upward, that is: in removing first the less 
thrifty, overtopped, diseased, and unpromising trees. In crowded 
groups, good-sized trees should sometimes be removed. The cooler 
part of the year affords the only reason that is safe against danger- 
ous insect menace following cutting operations. (See under ; * Insects. 
Disease, and Wind.") Such thinnings should be made as needed, 
usually at intervals of 5 to 10 years, each helping in the development 
of the final stand. The purpose of thinning is very much the same 
as that of the farmer in chopping his cotton or corn, namely, to 
give the remaining plants proper growing space and to secure 
the largest amount of the desired product. Trees growing wide 
apart in understocked stands may not need more than one thinning 
or they may not need any. If young longleaf stands contain unde- 
sirable kinds of trees, such as slow-growing, wide-spreading gums 
