720 The Importance of Insect-Capture [December, 
considered a mere accident, of no importance in the economy 
of the plant. Whether our zoophilists will on this account 
banish the Petunia from their gardens it remains to be 
seen. 
Nor is the mere capture of insects by plants the only 
point thus recognised. It is fully established that the little 
prisoners are made to undergo a kind of digestive process. 
Their bodies, whilst adhering to the flowers or leaves of 
their captors, are liquefied, and appear in that state to be 
absorbed into the tissues of the plants. 
But a third question has been left to some extent open. 
Do the inserts thus caught promote in any way the well- 
being of a carnivorous plant ? Would it flourish as well — 
or perhaps better — without inserts, or any equivalent animal 
matter, as with them ? On this important point botanists 
of eminence are by no means at one. Comparative experi- 
ments made upon the influence of a supply of white of egg 
have given fluctuating results. Some of the observers have 
found the plants thus fed decidedly benefitted as compared 
with other specimens from which such diet was withheld. 
Other experimentalists have been unable to perceive any 
difference ; and others, again, have even reported injury,' — 
the plants being apparently the worse for the absorption of 
animal matter. 
Results so diametrically opposite can be explained only 
on the assumption that the initial conditions of the plants 
selected for experiment must have been dissimilar. Further 
investigations were therefore needful, in which all sources 
of error should be eliminated. H. Busgen has endeavoured 
to secure a perfect uniformity by beginning his observations 
with the germination of the seed. 
The experiments were made upon the Sun-dew (Drosera 
rotundifolia), and the results are more immediately applicable 
to this species alone. The seeds of this plant are so light 
that a hundred weigh only 2 milligrammes, and a single 
seed only 0*02 milligramme. Differences in the dry weight 
of single seeds could therefore be safely negleCted, and the 
weight of the dry seed obtained at the end of the experiment 
from the fed and the unfed plants respectively could betaken 
as an accurate expression of the results. 
Ripe seeds of the Sun-dew were therefore collected at the 
end of October, 1880, and were kept in a cellar through the 
winter. Part of them were sown at the end of January, in 
a glass case, upon a piece of peat which had been pre- 
viously boiled in water. In May the seeds germinated, and 
by June 22nd there were so many plants of equal size that 
