The compound eyes of insects are, perhaps, among the most wonderful works of the Creator's hands. In those gigantic creatures whose fossilized bones are all now remaining to tell us of their history, the _mastodon_, and _megatherium_, and in such vast creatures as the elephant and the whale, we behold the great power, skill, and wisdom of God; but here, in a little object which we may cover with a pin's head or with a large grain of sand, is a more wonderful instance of His infinite and amazing power than all these. The eye of a dragon-fly is a good instance of a compound eye: and of all the beautiful, radiant, gem-like objects that can be selected for inspection through the microscope, this is the most exquisite. Professor Müller, the great German physiologist, has with wonderful patience and care dissected the eye of this insect, and has given a most beautiful account of its structure. On examining the eye of this insect, even with a good pocket magnifying glass, such as those commonly sold by opticians for a few shillings, it will be found to present the appearance of a beautiful net-work, or very fine grating, as is shown in the cut. When a greater magnifying power is employed, it will be seen that each space in this net-work is a six-sided or _hexagonal_ figure. Now each of these little spaces is filled by a beautiful minute lens of the same shape set in it. On making a perpendicular cut into the eye it has been found to consist of various layers: the outer layer is a hard clear membrane composed of a multitude of six-sided facets, each forming a more or less distinct cone-shaped cylinder, which runs towards the centre of the eye, as seen in the cut. Under this is a layer of coloured matter, sometimes of a violet, or green, or even reddish hue, which is pierced with as many holes as there are facets. Beneath this there is a varnish of a black colour, within which is a second layer of coloured matter; and in the space between this last and the first coloured layer the delicate fibres of the nerve of sight, or optic nerve, run. These fibres then converge together at the back of the eye into a single large nerve, which is connected with the insect's brain, and conveys the impression of sight to that organ.