253 
Water-conductivity in Sycamore Wood. 
rest of the ring of wood, with numerous smaller rays between. The typical 
xylem has a basis of wood fibres, interspersed fairly evenly with vessels, the 
tracheides and wood parenchyma being less conspicuous. Where the shoot 
is more than one year old the annual rings of wood are easily distinguished 
by the contrast in size and character between the elements on either side of 
Fig. 2. 
In this, and in the figures which follow, the identification-marks of the different curves will be found 
in the vertical columns A, B, c, &c. 
the line. The abundance of starch is a striking feature of the wood in the 
winter condition. 
The water-conducting elements are mostly of the nature of vessels; 
these have short wide segments, communicating by a single large round 
hole in each oblique dividing wall ; the rest of the wall is thickly covered with 
bordered pits, and strengthened internally with fine spiral bands. Typical 
spiral vessels occur next to the pith, followed by somewhat transitional 
elements with elongated pits. Next to the outer limit of the annual ring 
