248 
J. HOrKINSON-RATE OF GROWTH OF 
likely to have the closer-grained wood, and such wood ought to 
he the harder and more durable.* Observations on the rate of 
growth of these two species or varieties of oak should therefore be 
of considerable economic importance, and, when such observations 
have been made in Hertfordshire, they ought, I think, to be 
brought before our Society with a view to discussion, even if they 
do not lead to any very definite result. 
In the ‘Gardeners’ Chronicle’ for the 4th of March, 1905, 
Mr. H. Clinton Baker gave a table showing the rate of growth of 
a tree of Quercus pedunculata , grown from an acorn taken from the 
well-known Panshanger Oak, and of a tree of Quercus sessiliflora , 
grown from an acorn taken from a tree at Woburn, the two oaks 
growing at Bayfordbury 200 yards apart in sandy loam. 
This table is here reproduced. 
Quercus pedunculata , 
Q. sessiliflora, 
sown 1811. 
sown 1840. 
Year 
Circumference 
Circumference 
Circumference 
Circumference 
at 3 ft. 
at 5 ft. 
at 3 ft. 
at 5 ft. 
ft. 
in. 
ft. in. 
ft. 
in. 
ft. 
iD. 
1865 
7 
o 
6 7 
i 
IO 
i 
8 
1869 
7 
3 
6 io 
2 
6 
2 
4 
1871 
7 
6 
7 
2 
IO 
2 
7\ 
1872 
7 
8 
7 2 
3 
°§ 
2 
IO 
1878 
8 
3 
7 9 
4 
2 
3 
11 
1883 
8 
7 
8 i 
5 
ok 
4 
8 * 
1885 
8 
9 
8 2 
5 
3i 
5 
o 
1893 
8 
ii 
8 6 
6 
8 
6 
4t 
1900 
9 
7 
9 i 
8 
o 
7 
7 
1904 
9 
IO 
9 2j 
8 
ih 
8 
Mr. Clinton Baker remarks: “From the above table it appears 
that the sessile variety is rapidly gaining upon the pedunculate.” 
That is so undoubtedly, but a careful analysis of the table does not 
indicate that sessiliflora has at all ages been a more rapidly-growing 
tree than pedunculata. 
The trees are of very different ages, and it is evident that the 
younger tree ought to increase in circumference more rapidly than 
the older. For the 39 years over which this table extends it has 
done so. But at least two other questions arise: (1) What was 
the rate of growth of the two trees at the same age ? (2) What 
was the rate before the younger tree attained the age at which the 
older tree was first measured? The answers to these questions 
are conflicting, and lead to the further question: (3) What is the 
present tendency of the rate of growth ? 
It will be noticed that the intervals of measurement have varied 
greatly, in fact from one year (1871-72) to eight years (1885-93). 
* A contrary opinion has frequently been expressed. See ‘ Gardeners’ 
Chronicle,’ 29th Jan. and 5th Feb., 1842, and 22nd Sept., 1900. 
f 5 ft. 8 ins. and 5 ft. 4 ins. in the original table, but these figures are evidently 
erroneous, probably being misprints. 
