5 1 S Pieters . — Influence of Fruit-bearing on 
For a proper comparison of tissue-masses it was important 
that the sections should be cut at points having the same 
relative position. The basal zone of scars offered such 
a point, therefore only sections taken from this point were 
used for comparative measurements. 
The material was studied with reference to the following 
questions : — 
(1) Is the xylem-cylinder in a one-year-old fruit-bearing 
shoot less well developed than in a vegetative shoot of the 
same age and apparent vigour, and does it form a smaller 
proportion of the diameter of the shoot ? 
(2) What influence does fruit-bearing exert upon the 
lignification of cell-walls ? 
(3) Does the fruit-bearing shoot contain any supplementary 
mechanical tissue formed to supply a possible lack of develop- 
ment in the xylem-cylinder? 
Although a detailed histological study of the swollen part 
of the fruit-bearing shoot is not contemplated, a general sketch 
of the arrangement of tissue, as found in a shoot gathered 
during October, may properly precede the study of tissue- 
masses. 
At the base of the year’s growth the structure is fairly 
uniform on all sides. The cortex is compact, the xylem- 
cylinder is dense, and the walls of the wood-cells are well 
lignified. A little above the basal zone of scars, the cortex 
begins to enlarge and intercellular spaces become common. 
At this point also the wood-cells show thinner walls, though 
the thickness of the xylem-zone increases somewhat. Above 
the middle of the shoot, the symmetry of the wood-zone 
becomes disturbed to a marked degree. The bulk of the 
xylem is on the side of the lateral vegetative bud, and here 
also the wood-cells have thicker walls than those on the 
opposite side. Nearer the apex the walls of the wood-cells 
on the side nearest the fruit-stalk are still thinner, often indeed 
so thin that it becomes impossible to determine the exact 
position of the cambium. The cortex, on the other hand, 
greatly increases in size. The cells are larger, the intercellular 
