THE GIRTH-INCREASE OF TREES. 97 
The highest individual records for each month were—for April 
10, May 20, June 45, July 50, August 50, September 5. 
THE GENUS QUERCUS. 
Five species of Quercus, comprising ten young and four adult 
trees, have been under observation at various periods, two of 
which — Q. conferta and Q. Ilex—have been dealt with in my 
Paper of 1892. Taking the whole, the following have showed a 
decided preference for the second half-season :-— 
Quercus robur—four young trees 35 65 
» »» —one adult tree 38 62 
»»  conferta—three young trees 39 61 
»»  Cerris—two adult trees 40 60 
»»  rubra—one young tree 37 63 
25 75 
| »»  Tlex—one young tree 
On the other hand, of an apparently exceptional character 
were— 
| 
Quercus Cerris—one very young tree... 50 50 
| | « 
»»  robtr—one young tree, 1892-95 
In the first of these the result may be due to extreme youth, 
and we have already given reasons why the results in the second 
may be abnormal. 
Q. conferta is the most reliable species, as the three trees were 
Vigorous, quick growers, and behaved with great uniformity. In 
it, therefore, the superiority of the second half-season is well 
made out, and this is the more remarkable as its April growth 
Was steadier and larger than in any other kind of Oak or any 
other species under observation. In the other species of Oaks; 
indeed, the April increase was very small. 
Apparently exceptional points in the genus are the low rate 
of June-increase in a large proportion of the trees, but most 
marked in the twoadult examples of Q. Cerrzs and the old Craigie- 
hall tree, and the large percentage of August-increase in Q 
