470 
TROPICAL NATURE 
IX 
earth thus attached to birds’ feet several plants were raised. 
As showing the importance of this mode of transport, an 
experiment was made with six and three -fourths ounces of 
mud taken from the edge of a little pond, and it was found 
to contain the enormous number of five hundred and thirty- 
seven seeds of several distinct species ! This was proved by- 
keeping the mud under glass and pulling up each plant as it 
appeared, and at the end of six months the result was as 
given above. It was also found that small portions of aquatic 
plants were often entangled in the feet of birds, and to these 
as well as to the feet themselves, molluscs or their eggs were 
found to be attached, furnishing a mode of distribution for 
such organisms. Experiments were also made on the power 
of land-shells to resist the action of sea-water ; and we have 
already referred to the observations on volcanic dust carried 
far out to sea, illustrating the facilities for the wide extension 
by aerial currents of such plants as have very minute or very 
light seeds. 1 The facts are of so anomalous and apparently 
contradictory a character that, on the old hypothesis of the 
special independent creation of each species, no rational 
explanation of them could be found; and we may fairly 
claim that the clear and often detailed explanation which can 
be given by means of the theories and investigations of 
Darwin, lend a powerful support to his views, and go far to 
complete the demonstration of their correctness. 
Our space will not permit us to do more than advert to 
the numerous ingenious explanations and suggestions with 
which the Origin of Species abounds, such as, for example, the 
strange fact of so many of the beetles of Madeira being wing- 
less, while the same species, or their near allies on the con- 
tinent of Europe, have full powers of flight ; and that this is 
not due to any direct action of climate or physical conditions 
is proved by the equally curious fact that such species of 
insects as have wings in Maderia, have them rather larger 
than usual. Equally new and important is the Darwinian 
explanation of the form of the bees’ cell, which is shown to 
i This series of observations and experiments, supplemented by those of 
other observers, have been applied by the writer of this article to explain in 
some detail the remarkable phenomena presented by the distribution of 
animals and plants over the chief islands of the globe. See Island Life. 
Macmillan and Co. 
