e wonders of nature, and the triumphs of art are only to be
appreciated through the eyes, which have aptly been described as the
'windows of the soul.' Yet there are many who pass through life without
even realising what we may call the 'gilding' of the world--the delights
of colour. Quite a large number of people have no colour-sense, and are
unable to tell red, for instance, from green. The writer knows an
eminent botanist who is unable to tell the colours of the flowers he so
loves to study!

[Illustration: Fig. 1.--Head of Insect with eyes at side (greatly
magnified).]

How is it with the little people of the insect world in this matter?
Their eyes are constructed on an entirely different plan from ours. What
sort of a world is it that they look on? Taken as a whole, it would seem
that the insect inhabitants of our world see but very little of it; they
perceive it rather through the sense of smell. Only a very few insects,
such as dragon-flies, for example, see well, and even their length of
sight probably does not exceed six feet or so. They are a near-sighted
race. Moreover, they see moving objects more easily than stationary
ones.

[Illustration: Fig. 3.--Head of Drone Bee (greatly magnified). 'Ocelli'
at O.]

That many recognise colours there can be no doubt, and many show
preferences for certain colours. Bees show a great liking for blue, and
ants for violet. White butterflies appear to prefer white flowers, and
yellow butterflies yellow flowers. Orange and yellow are also attractive
to bees, whilst other colours seem to have no charms for them.

[Illustration: Fig. 2.--Head of Worker Bee (greatly magnified).]

[Illustration: Fig. 4.--Eye of Bibio Fly. 'Ocelli' at O (greatly
magnified).]

There is no doubt that some insects, however, see much more of the world
than others, for the eyes of the insects and their near relations, the
spiders and scorpions, are of two different kinds, and both kinds differ
greatly from ours in structure. Let us take the simple eye found in the
spider or scorpion, for an example, and look at it. If you catch a
spider, and carefully examine the front of his head, you will notice a
number of bead-like bodies of different sizes, arranged sometimes in the
form of a circle, sometimes on a prominent swelling or 'tubercle,' or it
may be in some other fashion, according to the kind of spider. These are
the eyes. A section cut through one of these eyes and placed under the
microscope