THE UPWARD TRANSLOCATION OF FOODS IN WOODY PLANTS 29 1 
From the table it seems that shoot growth is fairly vigorous when no 
food further back than that obtained from a branch about one centimeter 
in diameter is available. 
A somewhat similar experiment was tried with Fagus grandifolia. 
In this case the ringing was done before the buds had started. The data 
are reported in table 4. 
Table 4. Fagus grandifolia. April y to May 24. 
• Ave. Length of Ave. Number 
' s ' Shoot in Mm. of Leaves 
Twigs not ringed 186.4 6.6 
Ringed in the middle of the one-year-old wood 21.4 2.1 
Ringed at the base of the one-year-old wood 42.8 3.3 
Ringed in the wood three to five years old which in 
all cases was less than one centimeter in diameter 59. i 5.0 
These data as well as those reported in a previous paper (Curtis, 1920, 
tables 8-10) indicate that, when the ring is no further back than the 5- to 
1 0-year-old wood, the growth of the shoots above the ring approaches 
more and more nearly that of the unringed stems. It will be necessary to. 
use larger numbers of branches before one can attempt to state the distance 
from which food may be withdrawn. 
Even if one could use large numbers of uniform stems that have been 
grown under uniform conditions, it would be difficult to determine from 
ringing experiments alone as to the exact distance of upward movement, 
for a check in growth may result not from lack of food but from lack of 
water due to the fact that no new xylem would be formed in the region of 
the ring, because in some trees much of the water may be carried through 
this new xylem. It is to be noted that, in practically every case in which 
the wound was not well protected by a coating of paraffin, the growth was 
distinctly decreased as a result of a deficiency of water due to drying of the 
xylem. 
Not only is there considerable food stored in the twigs and young branches 
which becomes available for shoot growth in the spring, but the food manu- 
factured by the new leaves soon after they open also becomes available for 
continued shoot growth. 
The data reported in table 5 indicate that, soon after the shoots have 
started, much or all of the food necessary for continuing growth is produced 
by the leaves of that same shoot. 
In the experiments with apple and in the first of the experiments with 
Ligustrum, the growth of the ringed twigs with leaves is fully as great as 
that of the twigs not ringed. In fact, in these two cases the data indicate 
that ringing has even increased growth above that in the checks. This 
may be because the ring has increased the food supply by preventing removal 
of that produced by the new leaves. In the other experiments, with the ex- 
ception of the 1 91 8 experiment with Philadelphus, the growth of the ringed 
