A Contribution to the Study of Water-conductivity 
in Sycamore Wood. 
BY 
M. G. HOLMES, B.Sc. 
With thirteen Figures in the Text. 
T HE observations which form the subject of the present paper are 
based on an anatomical investigation of young Sycamore plants, 
Acer Pseudoplatanus ; they have special reference to the number, size, and 
distribution of the water-conducting elements in the wood, considered in its 
transverse aspect, at intervals throughout the stem. 
Material. 
The work was carried out on some Sycamore saplings, collected in the 
dormant condition in February, 1919, the plants being from two to five 
years old. The lengths of these shoots are indicated diagrammatically 
in Fig. 1. They are divided into segments, each corresponding with the 
growth in length during one season, and the segments are lettered a,b, c . . . 
from the base of the plant to its apex. Within each segment the internodes 
are numbered 1, 2, 3 . . . from the base of the segment upwards. It will be 
seen that the specimens S2 and S4 show three years’ growth, and S3 five 
years’, the growth being continued each spring by the development of the 
apical bud. S5 shows two years’ growth only ; the bud at the apex of the 
main stem, a , failed to develop in 1918, and the laterals reached a considerable 
length ; these are lettered b, c,d . . . The development of branches from 
the buds formed in the axils of the pairs of leaves at the nodes is more vigorous 
in the upper part of the segment, and as a rule the shoot formed from the 
apical bud is by far the strongest of its season. These specimens are com- 
parable in length with the stool shoots of Hazel and Ash, previously 
described (6 and 7 ), but the latter were of one season’s growth only, and 
investigation was confined to wood of the first year. The Sycamore 
specimens show a comparatively short growth in length to have taken place 
during one season, with comparatively few nodes, and in dealing with them 
it has been necessary to take into account wood of several years. 
[Annals of Botany, Vol. XXXV. No. CXXXVIII. April, 1931.] 
