Fig. 112.—Grasshopper in Flight.
Compare the first and second pairs of wings in shape, size, colour, thickness and use (Fig. [112]). How are the second wings folded so as to go under the first wings? About how many folds in each?
Draw a hind wing opened out.
Head. What is the shape of the head viewed from the front, the side, and above? Make sketches. What can you say of the neck? Is the head movable in all directions?
What is the position of the large eyes? Like the eyes of the crayfish, they are compound, with many facets. But the grasshopper has also three simple eyes, situated one in the middle of the forehead and one just above each antenna. They are too small to be seen without a hand lens. How does the grasshopper’s range of vision compare with that of the crayfish?
Fig. 113.
Are the antennæ flexible? What is their shape? Position? Are they segmented? Touch an antenna, a wing, a leg, and the abdomen in succession. Which seems to be the most sensitive to touch? The antennæ are for feeling. In some species of insects they also are organs of hearing and smelling.
The mouth parts of a grasshopper should be compared with the mouth parts of a beetle shown in Fig. [113], since they correspond closely. If the grasshopper is fed with a blade of fresh grass, the function of each organ may be plainly seen. It is almost impossible to understand these functions by studying a dead specimen, but a fresh specimen is much better than a dry one.
