86 CHRISTISON—OBSERVATIONS ON 
SPECIES WITH THE LARGEST PROPORTIONAL INCREASE IN JULY. 
| r 
1892, | 1893, | 1894. | 1895. | Total.| AY°""| § 3 
ag So 
| mM 
Populus fastigiata, | 55 | 50 | -40| -40| 1-85 | -48 | 375 
Cytisns Laburnum, | 25 | 15 | -35 | -10| -85 | -21 | 342 
Pyrus Aucuparia, | 1s | 25| -30| 20] 90 | -22 | 340 
WSlia soropua, .. -40 | -45 | -45 | -80 | 1-60 | -40 | 32-4 
Csculus Hippocastanum, 45 | 40); 40 | -30 | 1°55 | ‘39 | 32°0 
SPECIES WITH THE SMALLEST PROPORTIONAL INCREASE. 
Witkin: = 40 | 40 | 40 | -30/ 1:50 | 37 | 23° 
Robinia Pseudacacia, cen % | 35 | -20| 15 | 95 | 24 | 24°6 
Salix sp., cS Pa eee % | | 70 | ‘85 | 2°85 | -71 | 25-0 
| 
In July the variation in the comparative seasonal percentage 
of the species attains a decided minimum, being only from 
23°3 to 37°5, whereas in June, the next steadiest month, it is 
15°9 to 40°3. In July, in no less than eight species the seasonal 
p.c. lies between 30 and 32. 
Half an inch or upwards was attained in all four years by 
Salix and Prunus, in two years by Populus, and in one year by 
Fagus, Quercus rubra, and Acer campestris. The highest single 
score was °85 by Sa/zx. Forty-seven other records are between 
a quarter and half an inch, so that only twenty of the eighty 
records fell below a quarter of an inch. 
AUGUST. 
Aggregate Results, 20 Trees. 1892. | 1893. | 1894. | 1895. |Average. 
Total increase, .... ay see ae 4:90 4°35 3°80 4:20 4°31 
Percentage of seasonal increase, iv | SO 17°6 175 20°3 18-9 
The annual average increase is four inches and a half, about 
two-thirds that of June or July and double that of May, and the 
