Pruning. 237 
size, cut off at this line, will usually heal promptly, but if 
the cut is made much farther out, it will not. 
The cut should generally be made at right angles with 
the branch, rather than parallel to the supporting member, 
since it is important that the wound be no larger than is 
necessary. Wounds so large that they cannot heal promptly 
should be painted with the Bordeaux mixture (330) to pre- 
serve the wood. 
418, Unhealed Wounds Introduce Decay into the 
heartwood of trees. Since the cells of the heartwood con- ° 
tain no protoplasm (72), and are always moist, they form a 
congenial field for certain destructive fungi (321), that hav- 
ing once gained entrance, sooner or later destroy the heart- 
wood of the whole trunk, thus greatly weakening it, and 
preparing the way for the final destruction of the tree. 
419. Objects of Pruning. If intelligently performed, 
pruning has one of four objects in view, viz.: 
a— To change the form of the plant, as to outline, or den- 
sity (formative pruning (419A)). 
b— To stimulate development in some special part, as to 
promote the growth of wood, or the formation of flower-buds 
(stimulative pruning (426B)). 
c— To prevent some impending evil to the plant as to arrest 
or exclude disease (protective pruning (429)). 
d — To hasten maturity (maturative pruning (430)). 
A— FoRMATIVE PRUNING 
This aims to regulate the form of the plant with reference 
to outline or density, or to strength of stem. Pruning for out- 
dine, includes pruning for (a) symmetry or picturesqueness; (b) 
for stockiness or slenderness. 
