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number of little vessels, which are much finer than a baby's finest hair; and these delicate air tubes run all over the insect's body, crossing and interlacing each other, something like the light net-work of fibres to be seen in a leaf, after it has been robbed of its green covering by the moist wintry air.
This delicate lace-work of fine air tubes, is part of the living frame of an insect, as you may see in the picture of the water scorpion. And lest anything should press upon these minute vessels, and flatten them, so as to drive out the air, an exquisite contrivance of rings has been provided. These rings are small hard fibres, which are placed, one after another, along the inside of the air tubes, so as to form in them an entire lining. Sometimes they become a complete spiral lining rolled around the tubes like the spire of a corkscrew.
Wings.—The wings of insects are amongst the wonders of nature; they of an Insect, shewing are beautiful in their forms, and light in its lining of Rings. their make; they are easily folded up, and yet become broad when expanded; and thus formed to act like sails, they can bear the insect up, or waft it onwards through the air. And to give these delicate wings power to strike boldly upon the air, they are fastened by strong joints into the horny hoops of the thorax, or middle part of the body.
The wings of all insects are composed of a netted frame-work of many fine hollow air tubes, each tube being kept round and open by its internal spiral thread; and over both sides of this delicate net-work of air tubes is stretched a thin and transparent skin, making the wings look like gauze. A vast proportion of insects have no covering over this clear gauze; but, in the wings of butterflies and moths, it is completely spread over with plumes, or scales, of brilliant hues. These
Magnified Air Tube
scales are so fine, that to the naked eye they look like dust; but the microscope enables us to see that they
are regularly arranged in rows, which overlap one another, each separate scale being fixed tight by a root into the fine skin of the wing. The shape of these scales varies very much in different species; and they are so numerous, that upon a quarter of an inch of a peacock
butterfly's wing, (and a Different wing scales of Butterflies magnified. quarter of an inch
is this size) there were counted seventy rows, each row having ninety scales in it; thus making altogether 6300 scaly plumes on that little square.
Many of the beetle family burrow in the ground, and to protect their delicate sailing wings from injury, thick plates of a horny substance are placed over them. Some of these horny shields are brown, others are jet black, and others are of the most brilliant colours.
When a beetle wishes to fly, it draws tight a set of muscles that are attached to these horny cases, by which means they are lifted up, and then its neatly folded gauze wings are spread out, and by them the beetle is borne aloft in the air.
So exquisitely are the wings of insects adapted for the work of sailing through the air, that nothing can exceed the lightness, the grace, and the rapidity of their movements. Our common house flies seem jocund with mirth whilst they chase one another, and dance their giddy rounds in the sun-beams. One moment they are seen, the next they are lost in the distance: a dog runs fast, a horse gallops fast, but the busy fly that buzzes around their ears makes sport of their pace. Have you not seen a fly play over the head of a fasttrotting horse, then dart before him; then return and whirl round his head, and again be off! you know not
where ? It has been said, that when a fly is frightened, it will cut through the air at the rate of more than a mile in a minute. Even the heavy silk-worm moth can fly one hundred miles in a very short time.
LESSON 34.-INSECTS-PERFECT INSECTS.
Part 2. Eyes.—THE eyes of insects form a wonderful part of their bodies. Some of them are embedded or set in the head; some stand out on a kind of thin stalk: but no insect can roll or turn the eye in the socket, as we can turn or roll our eyes ; the
of an insect never moves. To make up for this want of action, a new plan is contrived. Each insect has usually two eyes, but if it be intended, like the whirl-gig, which lives in our ponds, to see objects both in the air and in the water, it is supplied with four. Some insects have nine, and others have not less than sixteen eyes.
Gyrenus, or The eyes of bees, butterflies, and dragon- Whirl-gig. flies, are made in such a way, that they become multiplying glasses. An immense number of little crystalline lenses,* (each one of which is not only shaped something like a watch-glass, but is also cut at the edges like a diamond,) are placed all over the outside of the eye-ball, so that the insect can see all round it at once. The microscope has enabled men to count the astonishing number of forty thousand of these lenses in the eyes of a butterfly, and the insect can see any object through each one of these lenses as distinctly as if it were itself a perfect eye, so that a butterfly may be said to have forty thousand eyes ! no wonder then that it flies away so quickly when we stretch out a hand to catch it; but in looking at a near object, it only uses one lens at a
* A lens is a transparent substance, with a surface rounded something like a watch glass.
time. A dragon fly has fourteen thousand lenses, whilst our house fly has four thousand; and twenty-five
thousand have been counted in the eye of one kind of beetle.
In order to discover whether objects can really be seen through each lens, a person named Puget placed the eye of a flea under a microscope, and in such a position that he could look through it; a soldier wbı happened at that moment to pass by, was instantly turned into an army of pigmies ; for whilst the lenses in the
flea's eye multiplied the numOne Eye-ball of a Butterfly, covered ber of objects, they also di
minished their size. The arch of a bridge became a spectacle more magnificent than anything that could be made by human skill, and the flame of a candle seemed the illumination of thousands of lamps. Leewenhoech tried the same beautiful experiment by looking in the same manner through the eye of a dragon fly; and he not only saw one house in the distance increased to many, by looking at it through the dragon fly's fourteen thousand lenses, but he saw each of these houses so distinctly, that he counted the windows, and could tell whether they were open or shut. Oh how perfect is our God in all His ways
, and how much does He delight in the high beauty and finish of His own works : consulting in the formation of every little feather, muscle, bone, or eye, not only the use, but even the joy, the convenience, and the happiness of His living creatures.
with its Lenses.
LESSON 35.-INSECTS—THEIR ANTENNÆ,
MOUTHS, AND FEET. Reducing-making small.
Incision-a place cut (Lat. incido, I cul Syphon—an instrument like a bent pipe, into).
used for drawing liquor from bar- Articulations-joints (Lat. artus, a joint) rels, etc.
Accomplish-perform. Antennæ.—All insects have two fine threads or lashes projecting from their heads: these are called their antennæ. In butterflies they are generally long, and are mostly ornamented with feathery additions; but on the greater number of insects they are plain and short. The antennæ on the heads of some beetles, which burrow in the ground, can be drawn, at the pleasure of the animal, into small cases contrived in the sides of the head, and by this means they are protected from rubbing against the hard earth. Various antennæ magnified,
These threads, or antennæ, are not made in one whole piece, but are generally hollow, jointed pieces, laid close upon one another, so that they can easily be bent in all directions. Insects seem to use their antennæ as feelers or guides. Before a beetle, which lives in the ground, comes out of his hole, he always appears to try how the air feels, by pushing out his antennæ. Some people think these threads enable insects to hear; certainly they do seem to give insects the power of talking to one another, for both ants and bees have been seen to cross their antenna upon meeting, as if in conversation, and afterwards to separate suddenly, as if bent on some important mission. The crossing of antennæ in a hive of bees, when the queen bee is lost, is evidently an affair of very hurrying and pressing importance
. The Mouth.—When insects are in their caterpillar state, their mouths have always teeth for cutting and grind