THE GIRTH-INCREASE OF TREES. 83 
SPECIES WITH THE LARGEST PROPORTIONAL INCREASE IN APRIL. 
- 
1892, | 1893, | 1894, | 1895. | Total.| AY" a: | 
age. a 
Quercus robur, 1 ws ee aS | 
3 Cerris, 10 5 5 20 Gi -fal tay 
Fraxinus excelsior, ... Fe. Fes 5 10 10 10 385 09 | 7:2 
Betals alba; 0 eh 
Quercus rubra, 
SPECIES WITH THE SMALLEST PROPORTIONAL INCREASE. 
(Esculus Hippocastanum, 
Tilia europea, 5 5 01; 10 
Populus fastigiata, 5 Sy SFY 40 
Acer Pseudoplatanus, 5 5 Hi} 12 
5 5 01 | 1°2 
Robinia Pseudaeacia, es 5 5 5 ae ‘W047 52 
Fagus sylvatica, | 
Large individual scores were scarcely to be expected. Salzx 
alone reached a quarter of an inch once, and did not exceed it, 
and ‘15, the next best score, was only recorded three times, once 
in Salzx and twice in Betula. 
MAY. 
| 
Aggregate Results, 20 Trees. 1892. | 1893. | 1894. | 1895. Average 
OWE intesiant = fo 2 eo. 2°75 4°70 2°55 2°95 2°24 
Percentage of seasonal increase, i. Poa 19°0 11°8 14:3 141 | 
The average annual increase is two inches and a quarter, or 
about three times greater than in April, and the range, though 
not so excessive as in that month, is still high. A total absence 
of increase was only recorded twice, but in sixty-two of the 
eighty observations the amount did not reach a quarter of an inch, 
and in thirteen it was only ‘05. 
