XI 
THE SPECIAL COLOURS OF PLANTS 
307 
forms the fruit of the strawberry; while the mulberry, pine¬ 
apple, and fig are examples of compound fruits formed in 
various ways from a dense mass of flowers. 
In all cases the seeds themselves are protected from injury 
by various devices. They are small and hard in the straw¬ 
berry, raspberry, currant, etc., and are readily swallowed 
among the copious pulp. In the grape they are hard and 
bitter; in the rose (hip) disagreeably hairy; in the orange 
tribe very bitter; and all these have a smooth, glutinous 
exterior which facilitates their being swallowed. When the 
seeds are larger and are eatable, they are enclosed in an 
excessively hard and thick covering, as in the various kinds 
of “stone ” fruit (plums, peaches, etc.), or in a very tough core, 
as in the apple. In the nutmeg of the Eastern Archipelago 
we have a curious adaptation to a single group of birds. The 
fruit is yellow, somewhat like an oval peach, but firm and 
hardly eatable. This splits open and shows the glossy 
black covering of the seed or nutmeg, over which spreads 
the bright scarlet arillus or “mace,” an adventitious growth 
of no use to the plant except to attract attention. Large 
fruit pigeons pluck out this seed and swallow it entire 
for the sake of the mace, while the large nutmeg passes 
through their bodies and germinates; and this has led to 
the wide distribution of wild nutmegs over New Guinea 
and the surrounding islands. 
In the restriction of bright colour to those edible fruits the 
eating of which is beneficial to the plant, we see the undoubted 
result of natural selection ; and this is the more evident when 
we find that the colour never appears till the fruit is ripe— 
that is, till the seeds 'within it are fully matured and in the 
best state for germination. Some brilliantly coloured fruits 
are poisonous, as in our bitter-sweet (Solanum dulcamara), 
cuckoo-pint (Arum) and the West Indian manchineel. Many 
of these are, no doubt, eaten by animals to whom they are 
harmless; and it has been suggested that even if some 
animals are poisoned by them the plant is benefited, since it 
not only gets dispersed, but finds, in the decaying body 
of its victim, a rich manure heap . 1 The particular colours 
of fruits are not, so far as we know, of any use to them other 
1 Grant Allen’s Colour Sense, p. 113. 
