64 CHRISTISON— ADDITIONAL OBSERVATIONS ON 
year—1899—and this rate was maintained for three years ; but a 
depression followed in 1902 and 1903 to 5 and 23, which I can 
only account for by disturbance from the removal of neighbouring 
trees and shrubs. Since then—from 1904 to 1906—there has 
been a progressive improvement to 93, 13, and 15}. 
QUERCUS ‘PEDUNCULATA.,.” No to. 
Always In the west border. Girthed 114 inches in 1893. For 
two years the rate was 172 mil., but in the next—1895—the 
increase was only 9. After pruning in 1896 it fell to 5, and 
the rate for eight years was only 6}. Finally, in the three years 
1904-—5-6, it has only improved to 1o. 
QUERCUS ILEX. No. 16. 
In the Quercetum. Girthed 4 inches in 1887 and increased at 
the rate of 16 mil. for seven years. Pruning in 1894 brought 
down the increase of that year to 4, and the rate for five years 
to 1898 was 72; in the next five it revived to 11, and in the final 
three—to 1906—to 18. 
ROBINIA PSEUDACACIA. No. 14. 
Always in the north border. Girthed 6} inches in 1892 and 
increased at the rate of 223 mil. for four years. It was only 
slightly pruned in 1896, and the general rate, which at that age 
would naturally be upwards, seemed but little affected, as for, 
the next five years it was 263; as, however, the amount of increase 
in 1895—the year before pruning—was 353, and in 1896—after 
the pruning—only 26, the difference, 9 mil., may represent the 
effect of the operation. 
TILIA EUROPCEA. No. 3. 
Always in the west border, near the Arboretum Lodge. Girthed 
14 inches in 1892 and had the satisfactory rate of 314 mil. for five 
years. After pruning, the rate fell for three years to 12; rallied 
for 2 to 18; fell for 2to 113; and for the final three—to 1906— 
the increases were very irregular—23, 63, and 12. 
