488 
White . — The Influence of Pollination on the 
Flowers were used from as widely separated orders as possible, so as 
to test the range of variation. Owing to the difficulty of preventing the 
pollination of the native Australian types growing in the open bush under 
their natural conditions, it was not possible to do much work with them. 
The apparatus used throughout the experiments was Aubert’s im- 
proved form of that of MM. G. Bonnier and L. Mangin for gas analysis. 
This apparatus has been described in full by Richards in his paper 
mentioned before. 
I found that, after becoming accustomed to this instrument by trying 
a few preliminary experiments, it worked with perfect satisfaction, provided 
that the mercury was pure and clean, and that the sodium hydrate and 
pyrogallol were used in the proper concentration. The complaints from 
certain quarters as to the lack of accuracy of the apparatus are due to in- 
attention to these precautions. 
Method of Experimenting. 
The anthers were removed from some of the flower buds while quite 
young and undehisced, and while the pistil was quite immature. 
In many cases this had to be done in extremely young buds, owing to 
the flowers being strongly protandrous, the anthers depositing their pollen 
on the still immature stigma, which pollen adhered, and would have served 
for autogamous fertilization even if access of pollen from other sources were 
cut off. 
The flowers from which the anthers had been removed were tied up 
securely in loose muslin bags, while other buds, generally on the same plant, 
of similar age were marked. 
These latter were watched, and directly the stigma was seen to be 
receptive were pollinated with the pollen from other flowers, either on the 
same or adjacent plants. These flowers were then left for a period extend- 
ing over a day and a half to six days, the length of the period depending 
on such conditions as temperature, atmospheric moisture, and the length of 
the style in those particular flowers. 
At the end of this period a certain number of the pollinated and un- 
pollinated flowers were removed, and their respiratory activity tested. 
Usually they were tested at once, in other cases they were kept with their 
stems in water for several hours before they were used. The peduncle, 
sepals, petals, and stamens or filaments were removed very carefully in 
order to prevent, as much as possible, any stimulating effect on the 
respiratory activity which might be caused by injury. Since the experi- 
ments usually were completed during the latent period of the wound- 
reaction, and since the gynaeceums were similarly treated in both cases, the 
disturbing action of this factor can be reasonably neglected. 
As a rule the complete gynaeceum was used, but in the case of flowers 
