6 CRAIB—REGIONAL SPREAD OF MOISTURE IN WooOD OF TREES. 
6. That the lowest section shows most markedly the pronounced 
accumulation of moisture in the centre. 
Although the graphs showed a transition in the matter of 
moisture content, more or less easily traceable from that of the 
lowest to that of the highest cut, it was not quite clear how the 
graphs should be correlated. Imbued with the prevalent idea 
that the dormant condition into which a tree passes on losing its 
leaves presupposes practically no movement of moisture during 
that period, I expected to find a more or less uniform distribu- 
tion of moisture in the transverse sections at least of the bole. 
And again I could not account for the large accumulation of 
moisture in the centre. Was it a relic of the active season just 
ended, a condition which would prevail throughout dormancy, 
or was it the commencement of some new movement consequent 
on the stoppage of foliar activity ? And another phase of the 
problem was: Were the results obtained characteristic of the 
species for the time of year or rather for this particular stage 
in the tree’s cycle, or were they peculiar to the particular 
tree examined ? 
I had these points particularly in mind when the second tree 
was felled in December. From it the following main results were 
obtained :— 
rt. That the central region ts the richest in moisture. 
2. That the moisture percentage of the centre increases 
upwards until the first cut fron: the crown is passed, and that 
above this there is a marked fall in moisture in that region. 
3. That the younger wood 1s no longer a marked maximum area. 
4. That the percentage of moisture of the extreme outside 
rings tends, on the whole, to increase upwards, and that this 
percentage is lower than in October. 
5. That there are indications in the lower cuts of a new dis- 
position of the moisture, viz. that the region of maximum moisture 
1s moving away from the centre, and | 
6. That this movement is most pronounced in the lowest cut, 
and becomes less marked upwards. 
What, then, has happened between October and December ? 
Comparison of the two sets of graphs for these months shows 
that the absolute moisture content is greater in December than 
in October. The additional moisture is probably due to root 
activity, the expression of which is shown in the younger wood 
in October, where, as already indicated, there lies one of the 
regions of maximum moisture. Reduced root activity is prob- 
ably responsible for the lower percentages of moisture of the 
es younger wood in December. Transpiration is then at its 
minimum and say; Ad the present, be a as negligible ; 
ifer that transpiration in winter is w. holly” 
