THE LIVING CRICKET
_Materials._
Living crickets in cages, with materials for food and concealment, and individual specimens in wide-mouth bottles or vials with cotton stoppers.
_Observations._
1. What is the average size and the general color of crickets?
2. Just what do they do when you try to catch them? What structures enable them to do these things?
3. Of the three pairs of legs, which extend sidewise for running or grasping, and which backward for jumping or climbing? What structures have the legs to enable them to do their work properly?
4. Notice how well developed the cricket"s wings are, and state how much they are used or how they influence the habits of the animal.
5. How many projecting spines are there on the hinder end of the body? Are they ornamental or useful? how? The female crickets have a special spear-shaped spine for depositing eggs.
6. In a column make a list of the senses (sight, feeling, etc.), and opposite each state what kind of an organ is used and where it is located. The ears are oblong white spots on the second long piece of the front legs.
7. Find out whether the cricket chews solid food or sucks liquid food, and whether it has biting jaws or protrusible lips. See whether it will attack a toothpick or your finger, and if the crickets have been confined long, whether there has been any attempt at cannabalism. Is its natural food animal or vegetable matter?
8. How do crickets chirp?
9. What work do they do in nature?
10. How does a baby cricket develop?
THE LIVING GRa.s.sHOPPER OR LOCUST
_Materials._
Individual specimens in wide-mouth bottles or jars, and other specimens in cages, with turf or foliage for food and concealment.
Simple lenses.
_Observations._
Notice the form and size of your specimen, its color, the number of its legs and of its feelers. Find the eyes; the two large eyes, a tiny one between the two feelers, and near the inner edge of each large eye, another tiny one. With a lens notice the markings on the large eyes. Find the mouth, and note its lips and finger-like feelers. Draw out an outer wing, and then carefully draw out the delicate under wing, allowing them both to fold into place again.
Under the wings find the circular or crescent-shaped membranes, the eardrums. Watch the gra.s.shopper"s body expand and contract in breathing, and find the small breathing holes along each side the body. Compare its rate of breathing with your own.
_Questions._
1. In what surroundings and how does the gra.s.shopper"s color protect it? What color markings has it which might serve for other gra.s.shoppers to see as signals? Explain how this signaling is done.
2. Explain how the legs are placed so as to act as springs in jumping and alighting.
3. What advantages in having the wings attached on the upper side and the legs on the under side of the body?
4. Explain how the small wings are protective, and how the large ones are protected.
5. Why is it better for the gra.s.shopper to have its mouth on the under side of its head instead of in front?
6. The large eyes are supposed to be far-sighted, the small ones near-sighted. State how the large eyes have the more advantageous position, and around how much of a circle they can see.
7. Describe how the gra.s.shopper breathes.
THE LIVING b.u.t.tERFLY OR MOTH
_Materials._
Individual specimens in large jars or cages, and other specimens in cages with foliage; simple lenses and a needle or pin.
_Observations._
b.u.t.terflies may generally be distinguished from moths by their habit of holding their wings together above them when at rest, by the feelers which are k.n.o.bbed at the end, and by the rather slender abdomen. Moths generally either fold their wings or hold them outstretched, their feelers are not k.n.o.bbed, and their bodies are rather bulky.
Observe these points in your specimen and the colors of the upper and under sides of the wings. Find the large eyes and examine them with a lens. With the needle or pin carefully uncoil the sucking tube which you may find under the head between two shields. Note the fuzziness of the body and the "dust" which covers the wings. Examine some of this dust under a lens.
_Questions._
1. Is your specimen a b.u.t.terfly or a moth? Prove your statement. If possible, give the name of your specimen.
2. Write a description of your specimen--its size, general color, and special color pattern.
3. Describe the sucking tube, or "proboscis," and name some flowers from which it might obtain nectar. Try to find out how the tube is operated.
4. Why is it that moths and b.u.t.terflies never bite? Do they sting?
How do you think they protect themselves from enemies?
5. State how the fuzz and dust on your specimen might influence a bird"s liking for it.
6. Contrast the size and usefulness of the wings of the b.u.t.terfly with those of some other insect you know about; contrast their legs; state how development of one set of structures may cause another set to be simple or feeble.
7. Most moths are active by night. What explanation can you give for their large eyes and expanded feelers? Feelers of insects may be for any or all of the following: touch, taste, smell, and hearing.
_Suggested drawings._