WINGS OF BEE.
The WINGS of insects are also most remarkable, and possess many peculiarities of structure which cannot be detected without the aid of a microscope. Take, for example, the wings of any hymenopterous insect, say those of a humble-bee, and see how beautiful is the structure which causes the four wings to be united into two when the insect is about to fly. In the [illustration] may be seen a pair of these wings, together with the row of hooks which bind them together. A still more magnified representation of the hooks is placed near the wings.
It is now ascertained that the wings of insects are connected with the breathing apparatus, and that the respiration of the insect extends even to the very tips of these singular organs, which are not modifications of existing limbs, as in the birds, but additional structures. The circulation of insects may often be seen by placing a portion of a transparent wing under a moderately high power. We have often seen it in the wing of the great water-beetle. A series of very beautiful preparations may be made in order to show the distinction between the wings of different insects; and as the orders of insects are founded upon their wings, there ought to be at least one example of each order. The proboscis of insects is always worthy of careful examination.
As to the breathing apparatus itself, the best mode of examining it is to open a caterpillar, remove a part of the large breathing tube which runs along each side, and place it under the microscope. It should always be taken so as to include one of the spiracles, or breathing-holes. An example of a breathing-tube, taken from a silk-worm, is given in the [illustration].
BREATHING-TUBE, SILKWORM.
Hairs of animals are very curious and interesting objects. They should be mounted in three modes—namely, dry transparent, dry opaque, and in Canada balsam, transparent. Be sure to procure some hair of the bat, the sheep, the mouse, the deer, the mole, and any of the weasel tribe. Many insects have very beautiful hair, but the most lovely hair in the animal kingdom is that which is obtained from the sea-mouse. Fish scales should also be procured, and specimens should be taken from the lateral line.