96 Gregory . — The Increase in Area of Leaves and 
Table I. 
Leaf 
number. 
1 
a 
3 
4 
Number of Plan 
5 6 
7 
8 
9 
10 
Average. 
2 
15.0 
i 3‘7 
1 4*4 
13-8 
14.8 
T 3‘7 
13-5 
13.8 
13*7 
140 
140 
15.2 
I 4"5 
I 5 '° 
14-8 
15-8 
13-3 
13-9 
r 4-3 
14-8 
14.4 
14.6 
17.9 
1 5-3 
16-0 
15*9 
16.6 
J 5*7 
i 5-4 
1 5*5 
16*9 
1 5*8 
16-1 
12*2 
jc*8 
11 *4 
n -4 
11.7 
io°6 . 
10.6 
9*9 
I 2*2 
io-6 
mi 
3 
17-6 
I6-.8 
1 5*4 
16.8 
i 7 *i 
16.2 
T 5’9 
14-6 
i6*6 
14*3 
i6*i 
20*5 
16*9 
17-4 
18.5 
17-7 
17.4 
17.4 
16.3 
1 8*5 
16.4 
17 *7 
- 
19-5 
18.4 
i6._9 
1 8*4 
19*0 
I 8*2 
16*9 
15-5 
i 9'3 
16-3 
17-8 
I2-I 
1 2.0 
10*4 
12*2 
12*4 
11*0 
10.5 
9'4 
12.4 
io-o 
11. 2 
4 
I /-3 
16.6 
15-0 
I5.2 
16-6 
14-3 
14-2 
T 4'3 
1 6* 2 
13-9 
15*4 
19.4 
18.6 
17.6 
l8-0 
17.8 
16.8 
16.4 
16*4 
18-6 
17.0 
i 7-7 
1 9 * 3 
I 7 *i 
I 5 , 5 
16.5 
18.4 
15*7 
1 6* 8 
15-8 
18.6 
14.9 
16-9 
12-3 
1 1. 1 
9.6 
ii *4 
12.7 
10.5 
11 *.5 
11*0 
12.2 
9.4 
11-2 
- •*> 
i 5‘9 
15.2 
1 5-3 
15*3 
i 6. < 9 
14-0 
13.6 
T 4*5 
it;. 6 
J 3'9 
15-0 
18-6 
16-9 
16*7 
18.4 
18.0 
15*8 
16-2 
16.0 
16.8 
15.8 
16-9 
17-2 
16-6 
15-5 
17.4 
17.7 
15.2 
17-0 
15-7 
14-0 
15.0 
16-1 
12. 1 
1 1 -3 
io-5 
12-2 
I 3 * 1 
io*4 
12.6 
io-6 
ii '5 
10-4 
II *5 
6 
10*0 
14.0 
13-4 
I 3 , ° 
11*2 
10.9 
12*1 
12.5 
12.6 
12*2 
12.2 
12.3 
15-9 
1 6. 1 
I4.8 
12.8 
I 2*8 
I3.8 
14.0 
14-2 
I 4 , 4 
14.1 
9*3 
I f*2 
15-2 
14-2 
I I-I 
II. - 
12.8 
13-8 
13-3 
13.2 
13.0 
— 
io *3 
9*4 
9 - 2 . 
6-5 
6-6 
8.2 
8,7 
9 *o 
9-2 
8.6 
7 
6*5 
10*7 
10*2 
IO’O 
7-5 
7.2 
8.8 
9-5 
9*5 
9*4 
8.9 
7*5 
13-0 
12-8 
1 1-5 
8-5 
8-6 
io-7 
10.7 
10.5 
10-9 
10-5 
6.4 
11. 8 
12-4 
9-5 
7.6 
6.9 
7-9 
9*3 
8.9 
10*0 
9.1 
8 
4-6 
7-8 
8-5 
6.1 
5-5 
4.8 
5*7 
6.4 
6-2 
6-8 
6.2 
4.2 
9-3 
9-8 
6-8 
5 *o 
5-2 
6.2 
7-2 
6.7 
7’9 
6-8 
3-8 
7"9 
8*3 
5*5 
4 ; 1 
4.0 
5 -o 
5*9 
5*8 
6.0 
5-5 
9 
3-5 
5 - 3 
5-6 
4.4 
3-9 
3-4 
4-0 
4*5 
4.4 
4*2 
4-3 
3-4 
5*4 
5-5 
4.0 
3-2 
3 -i 
3-8 
4*2 
4*3 
4 ’ 1 
4 ’ 1 
2.5 
5-3 
4 “ 7 
3*5 
2-5 
2 ’5 
3*2 
3-8 
3.6 
3*3 
3-5 
10 
3-7 
3-5 
3’9 
3*5 
3 *o 
2-5 
3.0 
2.8 
3*3 
3-4 
3-3 
2*3 
2-3 
3-7 
3.0 
2.8 
2-1 
2.2 
2.8 
3*5 
2.8 
2-3 
i-6 
2-5 
3 -o 
2;2 
1.8 
1-3 
1 *8 
1-6 
3-4 
2*2 
2-1 
11 
— 
— 
3*2 
2.4 
— 
— 
— 
— 
2*2 
— 
2*6 • 
— 
— 
2-6 
1-9 
— 
— 
— - 
— 
1.8 
— 
2*1 
— 
-T- 
1 -7 
i ’3 
— 
— 
— 
— 
L 5 
— 
i -5 
The columns 1-10 contain the entries for the linear dimensions of the 
leaves of the ten plants on the day specified, and, reading down each column, 
the three or four linear measurements of successive leaves from the oldest 
onwards are found. The entries for the cotyledons and first leaf have been 
omitted, as by this date they had attained their maximum size. In the last 
column, marked c average ’, are the means of the numbers occupying similar 
positions in each of the columns 1-10 ; for example, the first entry, 14-0, is 
the mean of the numbers 15-0, 13*7, ^14^4, &c., and represents the mean 
value of ‘ a ’ for the second leaf. 
From these mean values of the dimensions for each leaf the mean 
value for the area of each leaf is calculated. By adding together the mean 
