54 CHRISTISON—-OBSERVATIONS ON 
ACER PSEUDOPLATANUS. 
ANNUAL INCREMENTS. 
Total 
No. in List. 
~ 
n 
. es, | a, 1891. | 1892. | 1893. | 1894. | 1895. | 1896. 
13 | 0°26 25} 20 |. 2b 4 30-| 30 § 25} 20 | 50 0 25 } 2°45) -24 |136°50 
28 35 20 20 30 10 35 20 | “15 16 35 15 | 2°20) -22 | 64°25 
71 85 | 1-05 | 1°40 | 1°20 | 1°40 § 1°30 | 1°30 | 1:00 | 1:00 0 |10°50| 117 | 19°90 
74 70 | 1°10 | 1°55 | 1°40 | 155 § 1:40 | 1°45 | 1°55 15 30 4 10°70 | 1°34 | 19°25 
67 50 40 65 75 95 | ‘70 | 1°05 85 § 5°85) “73 | 11°40 
16 1°20 | 1°40 | 1°20 “15 5 3°80 | 1-27 | 16°10 
The Sycamore grows fairly well near Edinburgh, although it 
is rarely seen in the city gardens, and the largest trees in the 
Arboretum are of this species. Trees at several ages were 
tested. No. 67, only about a foot in girth in 1897, had grown 
at the rate of ‘73 for eight years; Nos. 16, 71,and 74, girthing one 
foot four to one foot eight inches in 1897, had grown, the first for 
three, the second for nine, and the third for eight years, at the 
rates of 1:26, 1°17, and 1°34, or on an average 1°26. These 
younger trees were only under observation in the second 
decade. : : 
No. 28, now five feet four inches in girth, was chosen in 1878 
as a handsome and thriving tree in a plantation belt opposite 
the Palm House, but, although it continued to look well, its rate 
all along has been surprisingly low; only °35 in the first decade 
and ‘22 in the second, or not much above a quarter of an inch 
annually for twenty years. 
The veteran, No. 13, chosen by Sir Robert in 1878, perhaps 
because it was the largest tree of any kind in the Garden, 
although even then past its best, is still presentable, and girths 
nearly eleven and a half feet. Its rough and scaling bark 
renders it unreliable for single years, but the average rate for 
the first decade was °26 and for the second -24, showing no very 
perceptible decline, and scarcely less, on the whole, than that of 
No, 28, which has just half its girth. 
The range of No. 67, the youngest specimen, was great, ‘50 to 
105, but that is, no doubt, because it was only growing out of 
