bits and mode of life in many cases
could not be overlooked or misunderstood. Nevertheless the book of
Nature was like some missal richly illuminated, but written in an
unknown tongue. The graceful forms of the letters, the beauty of the
colouring, excited our wonder and admiration; but of the true meaning
little was known to us; indeed we scarcely realised that there was any
meaning to decipher. Now glimpses of the truth are gradually revealing
themselves, we perceive that there is a reason, and in many cases we
know what the reason is, for every difference in form, in size, and in
colour; for every bone and every feather, almost for every hair.[12]

COLOUR

The colours of animals, generally, I believe, serve as a protection. In
some, however, they probably render them more attractive to their mates,
of which the Peacock is one of the most remarkable illustrations.

In richness of colour birds and insects vie even with flowers. "One fine
red admiral butterfly," says Jefferies,[13] "whose broad wings,
stretched out like fans, looked simply splendid floating round and round
the willows which marked the margin of a dry pool. His blue markings
were really blue--blue velvet--his red and the white stroke shone as if
sunbeams were in his wings. I wish there were more of these butterflies;
in summer, dry summer, when the flowers seem gone and the grass is not
so dear to us, and the leaves are dull with heat, a little colour is so
pleasant. To me colour is a sort of food; every spot of colour is a drop
of wine to the spirit."

The varied colours which add so much to the beauty of animals and
plants are not only thus a delight to the eye, but afford us also some
of the most interesting problems in Natural History. Some probably are
not in themselves of any direct advantage. The brilliant mother-of-pearl
of certain shells, which during life is completely hidden, the rich
colours of some internal organs of animals, are not perhaps of any
direct benefit, but are incidental, like the rich and brilliant hues of
many minerals and precious stones.

But although this may be true, I believe that most of these colours are
now of some advantage. "The black back and silvery belly of fishes" have
been recently referred to by a distinguished naturalist as being
obviously of no direct benefit. I should on the contrary have quoted
this case as one where the advantage was obvious. The dark back renders
the fish less conspicuous to an eye