524 Pieters. — Influence of Fruit- bearing on 
The diameter of the fruit-bearing shoots at the base is 
much greater than that of the vegetative shoots. This is 
largely because the swelling begins at the base, involving the 
basal zone of scars. It is impossible to get entirely below it 
and still be within the year’s growth. 
The tables show that the amount of woody tissue is greater 
in the fruit-bearing than in the vegetative shoots, although 
the percentage is slightly less. This is due primarily to the 
increased size of the pith, since the proportion of cortex 
is also greatest in the vegetative shoots. The cortex, however, 
increases rapidly in size toward the middle of the shoot, and 
soon greatly exceeds that in the vegetative shoot. The walls 
of the wood-cells in the fruit-bearing shoot at the base were 
of usual thickness, as far as could be ascertained by careful 
inspection. No measurements were made. 
It is clear that the base of the fruit-bearing shoot is not 
mechanically weak. 
Plum . — The material for this work was collected in the 
latter part of July. Two sets of shoots were taken, both in 
their third year of growth. One set bore mature fruit at the 
time of collecting, and the other had borne no fruit that season. 
In the Plum, as in the Peach, the axis of the fruit-bud is 
but slightly developed, and the fruit-stalk seems to proceed 
directly from the branch upon which the bud is borne. The 
sections of the Plum were taken 1 or 2 centimetres below the 
point of attachment of the fruit, and, in the vegetative shoot, 
at a point as nearly similar to this as possible. The tissue 
from | to 1 centimetre below the fruit shows the effect 
of fruit-bearing. The zone of cortex is larger than either 
above or below this point ; the zone of xylem and the pith are 
also larger. The development of all the tissues is greatest on 
the side toward the fruit, making the section of the stem 
at this point oval instead of circular. The walls of these 
wood-cells are thin and but little lignified. The measure- 
ments were taken from sections cut below the swollen portion 
in order that those from fruit-bearing and from vegetative 
shoots might be comparable. 
