CRAIB—REGIONAL SPREAD OF MOISTURE IN Woop OF TREES. 13 
1. Platanus acerifolia, about forty years old, felled on the 
same day as the October Acer, gave the same general result as 
the Acer, viz. a decided accumulation of moisture in the central 
area, and what appeared to be the commencement of storage 
in this region in the two next higher cuts. The percentages 
were higher throughout the lowest cut, but the chief differences 
of detail were that there was a decline in the percentage right 
to the storage region, and this region was not the actual centre 
but some little distance out from the centre. Was the latter 
detail influenced by the fact that the tree had lost the top of 
its crown a year or two previously ? 
2. Betula pubescens x verrucosa (felled 2nd January 1918) 
and Betula verrucosa (felled 24th January 1918) have given, as 
far as the results have been worked out, very similar graphs to 
those of the December Acer. 
3. Crataegus Oxyacantha (felled 5th March 1918). Here once 
more I find myself wandering beyond the limits set in this paper, 
since the buds were just open on this tree at the time it was 
felled. However, the results, as far as at present available, tend 
to confirm the wider application of these new facts since they are 
similar to those of the Acer in the same condition. 
Of true heart-wood trees I have but scanty information. 
1. A very old tree of Ulmus montana was felled in November, 
but unfortunately the centre was not sound. The results 
showed a sudden and very marked increase in moisture per- 
centage immediately on entering the heart-wood. 
2. Quercus cerris, thirty-four years old, felled 8th March 
1918, gave results which, so far as available, correspond exactly 
with those of the similar cuts in the December Acer. From a 
solitary example, and that one with only some 6 cm. of heart- 
wood at the base of the trunk, it would be rash to draw con- 
clusions, and yet the similarity of the curves suggests that in 
this case sap-wood and heart-wood are indistinguishable in 
their functions as regards storage and movement of moisture, 
t.e. the results gave no indications of two regions functioning 
- differently. 
From such. evidence it would be unwise.to draw inferences 
with regard to heart-wood trees. Arrangements have, however, 
been made to carry out as far as possible during this year the 
examination of a series of heart-wood trees on the same lines 
as that done for Acer. Whether heart-wood really functions 
uniformly with the sap-wood in these moisture movements 
cannot be answered until a series of some heart-wood trees 
has been examined. : 
Although this paper has been written from the more practical 
and utilitarian side, yet the new facts brought to light give rise 
