54. BULLETIN 816, U. S. DEPARTMENT OF AGRICULTURE. 
made to change or distort a tree from its normal habit of growth. 
Successful pruning will accentuate rather than disguise a tree’s 
characteristics. HSH Pesta ee 
All cuts should be made so that no stubs or protuberances are left 
to prevent quick healing. Small wounds need no after treatment if 
the cut is well made. Large wounds should have the wood of the 
center of the cut well protected to prevent decay until the new growth 
has had an opportunity to heal over the cut. An application made to 
the center of the cut. 
to preserve the wood 
should not be per- 
mitted to come near 
the cambium layer 
or inner bark, espe- 
cially of soft-wooded 
trees like the tulip 
and magnolia, as the 
oil or other sub- 
stances contained in 
the paint, tar, or 
other covering May 
spread to the cam- 
bium layer and kill 
it. Itis well not to 
make any applica- 
tion within half an 
inch of the outside 
of the wound unless 
the coating has been 
—_ __ thoroughly tested. 
Fic. 37.—Part of a tree trunk showing proper and improper methods Dead wood should 
of removing old limbs. Although healing has started on the stub : 
(at the right) it is likely to proceed very slowly. The nearer the be entirely removed, 
cut is to the tree the larger the wound but the less conspicuous the the cut being made 
stub will be when healed. through 00 d live 
tissue. Removing such wood frequently exposes decayed cavities, 
usually from bad stubs or injuries which have started decay that has 
followed back to the main limbs or the trunk. The treatment of 
such cavities is the province of tree surgery and is discussed in 
another publication." 
One source of trouble with a large tree that has developed with 
two trunks or branches instead of three or more is the liability of their 
splitting apart in the crotch. This is especially characteristic of the 
elm. Careful attention to the early pruning of trees may eliminate 
1 Collins, J. F. Practical tree surgery. In U.S. Dept. Agr. Yearbook, 1913, pp. 163-190, pl. 16-22. 
Published as Yearbook Separate 622, obtainable from the Superintendent of Decuments for 10cents in coin. 
