49i 
Respiratory Activity of the Gynaeceum. 
similar irregularities occurred, due in all probability to local variations or to 
nutritional factors. The position of the flower on the plant, whether it is 
terminal or lateral at the base or apex, and whether it is shaded or exposed, 
are all factors which influence the vigour of flowers, and hence also their 
respiratory activities. 
The average ratios for the respiratory activity of the pollinated and 
unpollinated material are in this case as 112 : 69. The respiratory quotient 
is less than unity, and is throughout higher in the pollinated than in the 
unpollinated gynaeceums, the average difference being practically the same 
on both the fourth and fifth days. 
GYNAECEUMS OF PELARGONIUM ZONALE , L'HfeRiT. 
Weight of 
material in 
milligrams. 
Date. 
Condition of 
material. 
\ 
Tempera- 
ture . 
Vol. of air 
enclosed. 
Vol. per cent . of 
0 2 absorbed by 
material. 
Milligrams of C0 2 
produced by 10 
grms. of material 
per hour. 
Duration of 
experiment. 
Resp. quotient 
volume. 
0 2 
30 
i 
25/3/07 
' 
Pollinated flowers 
opened 5 days. 
18 0 C. 
j 3 c.c. 
2-7 ; 
OJ 
00 
6 
\ 2 hours 
.92 
. 
2 5 
25/3/07 
Unpollinated flowers 
opened 5 days 
1 8° C. 
3 c.c. 
2-0 
4.9 
2 hours 
•75 ; 
40 
3/4/07 
Pollinated flowers 
opened 6 days 
i7°C, 
3-5 c.c. 
i-6 
22.0 
2 hours 
1-2 
: 
20 
3/4/07 
Unpollinated flowers 
opened 6 days 
i7°C. 
3.5 c.c. 
1.9 
4.6 
2 hours 
■I 
30 
3/4/07 
Pollinated flowers 
opened 6 days 
i7°C. 
j 3-5 c.c. 
2.9 
35-o 
2 hours 
1-2 
20 
3/4/07 
1 
Unpollinated flowers 
opened 6 days 
O 
O 
\ 3-5 c.c. 
1 
2.4 
6-8 
2 hours 
.28 
Conspicuous irregularities are noticeable in the respiratory quotient of 
Pelargonium zonale. These were caused mainly by the extremely large 
differences between the C 0 2 production in the pollinated and unpollinated 
material, the differences between the 0 2 absorption being less pronounced. 
The average relative respiratory activities were : — pollinated, 950 ; un- 
pollinated, 163 ; the difference being more pronounced on the fifth day 
than on the sixth day. The respiratory quotient on the fifth day was 
nearly the same in both lots of material, but on the sixth day rose above 
unity in the case of the pollinated, and fell to quite a small fraction in the 
case of the unpollinated material. Possibly the stimulus of pollination 
hastens or induces the passage of a certain amount of oily food material to 
the gynaeceum. 
N n 2 
