Peculiar Growth Habit and the Anatomy of Dog’s Mercury. 197 
TABLE 3. 
Measurement, in cms., of the length of the basal vegetative, 
middle inflorescence, and terminal vegetative regions of female 
plants of Mercurialis perennis. Plants growing in less shaded 
position than those recorded in Table 1. 
Basal region. 
Flowering region. 
Terminal region. 
Total. 
14-9 
• 13*7 
1-2 
29-8 
17-9 
n -7 
1 -o 
30-6 
17-3 
8-i 
1-0 
26-4 
13-2 
n-8 
9-8 
34-8 
17-5 
5-8 
5-5 
28-8 
10-4 
n -7 
2-6 
24-7 
14-9 
12-7 
i ’5 
29-1 
18-1 
7-8 
3-7 
29-6 
27-9 
2-0 
1-7 
31-6 
13-4 
6-i 
i-8 
21-3 
20-8 
6-4 
1-9 
29-1 
18-5 
8-4 
6-5 
33-4 
15-7 
9-6 
1-9 
27-2 
13*5 
14-8 
5-9 
34*2 
Mean ... 16-71 
9-33 
1 0 
Cl 
1 CO 
29-33 
TABLE 
4 - 
Male Mercurialis perennis. In less shaded position than 
plants recorded 
in Table 2, and 
close to plants 
in Table 3. 
Basal region. 
Flowering region. 
Terminal region. 
Total. 
12-2 
18-8 
15-4 
46-4 
l8 -2 
5-8 
15-8 
39-8 
15-2 
6-2 
18-8 
40-2 
2 4 -7 
7-4 
II-O 
43 -i 
20-1 
ii *3 
10-9 
42-3 
20-8 
6-i 
16-6 
43-5 
12 ‘9 
10-4 
14-7 
38-0 
15-7 
16-3 
10-7 
42-7 
io-o 
14-9 
I 5'5 
4°‘4 
15.8 
5-2 
20-8 
41-8 
21 -O 
6-0 
7-6 
34-6 
15-3 
io-o 
8-8 
34 -i 
15-8 
5-9 
14-4 
36-1 
19-1 
7-3 
I 3 ' 1 
39-5 
Mean ... 16-91 
9-40 
13-86 
4 °- i 7 
It will be observed that in each set of figures the total 
height of the male plant is definitely greater than that of the 
female, and that the difference is mainly due to the greater 
elongation growth of the shoot produced above the flowering 
region, the basal and inflorescence regions varying incon- 
siderably. This suggests that the development of the fruit 
reduces the elongation growth of the shoot developing above. 
This reduction is probably due to competition for food supply 
between the developing fruits and the growing point. 
1933 Sept. 1 
