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wounds are carefully dressed and borers kept out, decay may 
usually be avoided, though the loss of food cannot be replaced, 
An overgrown top should usually be corrected by thinning out 
some of the longer branches. This is better than heading then 
back, because the effect of the latter process is to destroy the 
beauty of the tree and to produce a dense, objectionable cluster 
of branches, as well as to open a sure road for the entrance of 
disease. The cut end of a branch rarely heals over; the adjacent 
parts die, and decay gradually extends to the trunk. 
Branches to be removed should be cut off even with the trunk, 
This rule should be invariably followed with all trees, conifers 
not excepted, even though the labor be increased five-fo 
the branch being made first, and followed by another above and 
about a foot farther from the trunk. A dead limb should be cut 
back even with the shoulder - its base. 
The work of pruning is no means complete until the 
wounds are carefully smo re down and properly dressed. 
This treatment enables the healing tissue to cover the wounds in 
the shortest possible time and prevents the decay of the wood 
while healing is taking place. Exposed wood gradually loses 
water and cracks are produced in which dust and moisture collect 
and form a substratum for the growth of bacteria and moulds. 
Later, the spores of larger fungi enter and by developing in this 
mass of decayed wood become sufficiently vigorous to attack the 
heart-wood and thus pass into the trunk of the tree 
If some substance is applied to the wound which will prevent 
the evaporation of water and the consequent checking, decay 
may be avoided. Various mixtures have been used for this pur- 
pose, of which lead-paint and coal-tar are probably the best. 
Both are antiseptic as well as protective, if applied in thick layers. 
In case of large wounds, which require several years to heal, it 
is well to put on a second coat after two or three years. Thin 
coal-tar is not suitable for this purpose as it does not prevent the 
evaporation of water. It may be thickened by burning in an 
iron kettle. Coal-tar does not injure the tissues to any appre- 
