FLORIDA STATE HORTICULTURAL SOCIETY. 
lOI 
red spots, the soil is acid; if the red has 
been turned blue, the soil is alkaline, and 
if neither has been chang’ed the soil may 
be neutral. Do not put the fingers or 
hand upon the end of the paper that is to 
be placed in the soil. 
DEFINITE EXPERIMENTS. 
The Experiment Station is beginning 
some systematic work with reference to 
the effect o'f lime on acid soils, and we 
hope at no distant day to be able to report 
some definite results. 
We shall be glad of the co-operation of 
any of the members of this society who 
are interested in the subject. 
Principles in Tree Pruning. 
By H* Harold Hume. 
Mr. President, Ladies and Gentlemen : 
To understand the underlying princi¬ 
ples of pruning, we should know some¬ 
thing of the structure of the trunk of the 
tree, and its branches. If we examine a 
cross section of the wood of an oldl tree, 
we note in the centre, the pitch surround¬ 
ed by the heart wood. Around this is a 
band of sap wood and outside of all a 
protecting cover, the bark. Just between 
the bark and sap-wood lies the cambium 
layer in which all growth takes place. 
From it, wood is formed on one side and 
bark on the other. 
WHERE A BRANCH STARTS. 
Branches always develop from budls 
and, where produced normally, the branch 
is formed from a bud developed the year 
previous. In consequence the base of the 
branch is generally one year younger than 
the part of the tree on which it grows. 
We commonly refer to the portion of the 
branch extending into the wood as a knot. 
This knot has its origin at the pith. If 
we examine a section cut through the 
branch and the trunk on which it grows, 
we will note that the grain of the knot 
runs tO’ the center of the tree. 
From this we learn the lesson, that if 
for any reason the branch should die and 
rotting should commence, that the rot 
will extend along the knot into the center 
of the tree and) there continue its work 
in the trunk. 
THE HEALING OF THE WOUND. 
With the removal of the branch all in¬ 
ner portions of the tree are exposed by 
the wound made. The bark being re¬ 
moved, the wood is laid bare and decay 
has an opportunity to begin its work. 
Every tree in healthy, active growth 
makes an effort to cover over the wound. 
The healing does not take place over the 
whole surface. A tiny ring, or cushion of 
woody tissue protected by bark, is thrown 
out from the cambium layer all around 
the wound. This is called the callus. 
This callus gradually shoves out, increases 
in size and) ring after ring of growth is 
