257 
Water-conductivity in Sycamore Wood . 
was done in the wrong place, so that they are in all cases rather too low. 
This makes the figures for c also too low, but the remaining figures are not 
affected. Thus, while retaining a similar general shape, but not exactly the 
same, the curves for B and C in all the diagrams ought to be higher. The 
numbers given to represent the limits in variation in the values for c 
( 7 , p. 263) should be as follows : 
Ash 2.32 to 12.25 % (instead of 1.68 to 9.5) 
Hazel 4.09 to 25.4 % (instead of 3.21 to 20*26) 
Further corrected figures will be given below, for comparison with 
those obtained for Sycamore. This correction does not, however, materially 
affect the general conclusions of the earlier papers. 1 
Returning to the Sycamore, it will be obvious that, when it comes 
to any part of the stem which is more than one year old, equal intervals on 
the base line do not any longer correspond with equal numbers of leaves 
supplied ; some nodes are bare, while others have one or two lateral 
1 The incorrect formula was based on the corresponding values for E and E, as follows : 
/A\2 
B — Fx 77 ^ -- io 6 mm 2 (E being in ja). 
C was worked out from the value found for B . 
The correct calculation is as follows : 
Suppose that the diameters are measured at intervals of e \x, and let F = (j\+ / 2 + / 3 + . . .)> in which 
/i> / 2 > fat ... represent the numbers of elements having diameters of 1 e, 2 e, 3 e,... fx ; then 
B -/, . (£)* + A - ( 2 y Vs rr (-ff + V 
- + 2 2 /2 + 3 V 3 +...') mm 2 . 
4 x IO 
S 
