PROPAGATION OF TREES. 225 
at the commencement of winter, as at this season any 
wounds formed will readily heal, owing to the influen- 
ces of climate brought to bear upon the exposed parts. 
Some species, however, owing to the sparseness of sap- 
circulation in their systems, may be pruned at any time 
without injury; but the great desideratum in all in- 
stances is to effect the operation without having any 
cause to fear the result. 
In pruning large trees, when the wounds are of con- 
siderable size, it is requisite that they be protected from 
the decomposing influence of moisture by applying a 
thin coat of common grafting-wax to the exposed wood ; 
or varnishing the parts with a preparation of gum-shel- 
lac dissolved in alcohol will fill and dry the pores of the 
wound and exclude any injurious agencies. 
The pruning of evergreens is not so generally neces- 
sary as for deciduous trees, the object to be obtained in 
the cultivation of them being so different that only the 
matter of taste will serve as a guide. Their principal uses 
being ornament and shelter, these requirements necessi- 
tate but little work for the knife, as for such purposes 
the trees are more beneficial and attractive when al- 
lowed to retain their natural fantastic diversity. 
