obtained, open asparagus beds would be superfluous, and the training
of fruit [15] trees against the most favourable of mouth walls, a
waste of time and trouble.

But it is extremely important to note that, the state of nature
remaining the same, if the produce does not satisfy the gardener, it
may be made to approach his ideal more closely. Although the struggle
for existence may be at end, the possibility of progress remains. In
discussions on these topics, it is often strangely forgotten that the
essential conditions of the modification, or evolution, of living
things are variation and hereditary transmission. Selection is the
means by which certain variations are favoured and their progeny
preserved. But the struggle for existence is only one of the means by
which selection may be effected. The endless varieties of cultivated
flowers, fruits, roots, tubers, and bulbs are not products of
selection by means of the struggle for existence, but of direct
selection, in view of an ideal of utility or beauty. Amidst a multitude
of plants, occupying the same station and subjected to the same
conditions, in the garden, varieties arise. The varieties tending in a
given direction are preserved, and the rest are destroyed. And the
same process takes place among the varieties until, for example, the
wild kale becomes a cabbage, or the wild Viola tricolor, a prize
pansy.

[16]


V.

The process of colonisation presents analogies to the formation of a