493 
Respiratory Activity of the Gynaeceum. 
In the case of Begonia semper jlorens 45 milligrams of carbon-dioxide 
were produced by the pollinated gynaeceums, as compared with 11 milli- 
grams obtained from an equal weight of the unpollinated. 
The average respiratory quotients of the pollinated specimens and un- 
pollinated specimens, respectively, are as -73 : -31. 
GYNAECEUMS OF TECOMA CAPENSIS, R. Brown 
Weight of 
material in 
milligrams. 
Date Condition of 
material. 
Tempera- 
ture. 
*1 
^ Vo 
£§ 
Vol. per cent, of 
0 2 absorbed by 
material. 
Milligrams of C 0 2 
produced by 10 
grms. of material 
per hour. 
Duration of 
Experiment. 
I 
Si 
1 
* § I 
to 10 1 
O I 
50 
2 7 / 3/°7 Pollinated flowers 
1 opened 5 days 
12.5 0 C. 
6 c.c. 
3.0 
3c-o 
2 hours 
•53 
60 
27/3/07 Unpollinated flowers 
opened 5 days 
12-5° C. 
6 c.c 
2.9 
15.0 
2 hours 
•34 
60 
2 7 / 3/°7 Pollinated flowers 
opened 5 days 
12.5 0 C. 
5 c.c. 
1.9 
7.0 
2 hours 
•36 
60 
27/3/07 ! Unpollinated flowers 
1 _ opened 5 days 
I2. 5 °C. 
4 c.c. 
1.9 
3 -i 
2 hours 
•1 1 
60 
' 
4/4/07 Pollinated flowers 
opened 5 days 
i6. 5 °C 
5 c.c. 
i -3 
4.6 
2 hours 
•35 
65 
4/4/07 Unpollinated flowers 
opened 5 days 
i6. 5 °C. 
5 c.c. 
1 -o 
2.8 
2 hours 
.28 | 
. 1 
In Tecoma capensis , out of two pairs of experiments performed on the 
same day there was a pronounced difference in the carbon-dioxide pro- 
duction between the first and second pair. The fall in the oxygen 
absorption was not so marked, but it is evident that the respiratory activity 
rapidly decreased in the flowers cut and kept with their cut ends under 
water. Whether this was due to a closure of stomata, or to the consumption 
of the presumably limited supply of food material available, is difficult to 
say. In any case the respiratory activities of the pollinated and unpollinated 
gynaeceums are as 416 : 209, and the average respiratory quotients as 
0-41 : 0-24. 
