154 
TREES AS GOOD CITIZENS 
of receiving nourishment, while the lower edge is out of the 
direct channel and is less generously supplied. Thus it is 
obvious that a tongue of bark, projecting above the lower 
edge of a wound or bark below a broad wound, cannot 
receive its share of sap, and must therefore languish and 
die. Even on the upper edge a projection is undesirable, 
but it has better chance than a similar tongue on the 
lower edge. From this it is clear that the wound should 
have its edges so trimmed as to make as little top and 
bottom as possible. In other words, the wound which 
has its longest dimension parallel with the limb and the 
shortest dimension across it, is the one which will heal 
most rapidly. These factors should be borne in mind in 
trimming the edges. 
In connection with injuries to the bark it must be 
remembered that bark which has been seriously damaged, 
or which has been torn loose from the trunk, can never 
be made to resume its growth. Efforts are sometimes 
made to induce growth by fastening the bark to the tree 
with nails or otherwise. This not only does no good, but 
works still further damage by making an attractive rendez¬ 
vous for insects and decay. The only thing to do in a case 
of this kind is to cut away the loose and injured bark and 
apply protective coverings. 
Freezing sometimes does more or less serious harm to 
trees which have been transplanted from warm climates 
into regions of severe cold. Cracks or splits in the bark 
and wood, caused by alternate freezing and thawing, 
invite disease and decay. The wounds should be treated 
as soon as they become apparent, which is usually during 
the summer, when the bark splits away from the wood. 
Injured parts should be cut away and the surface given 
a protective coating. Wrapping the trunk of a tree with 
burlap or straw, before cold weather, will prevent frost 
