Scouting For Girls, Official Handbook of the Girl Scouts Part 66

The Gla.s.s "Snake" of the Central and Southern States is a peculiar lizard in that it has no legs. That it is able, after being broken to pieces, to collect itself together again and continue to live is another old myth.

[Ill.u.s.tration: DIAMOND-BACKED TERRAPIN

Range: Salt marshes of the Atlantic Coast and Gulf of Mexico from Ma.s.sachusetts to Texas.]

About a dozen kinds of Horned "Toads" are found in the western portions of the United States. Although toad-like in the shape of their bodies and in some of their habits, they are really lizards.

The American Chameleon or "Green" Lizard, which ranges in this country in the coastal regions from North Carolina to the Rio Grande River, has a remarkable power of changing the color of its skin through shades of brown, gray, and green. In fact, it is said to rival or possibly excel the true chameleons of the Old World.

For treatment of the Snakes see Woodcraft, Section XIII.

FISHES

_"It is not all of fis.h.i.+ng to fish."_

[Ill.u.s.tration: PADDLE-FISH

So-called from the paddle-like or spoon-shaped snout. Eggs used for caviar. Range: The Mississippi River and its tributaries.]

The fishes are the lowest of the true vertebrates or animals with backbones, and all live in the water. They do not have lungs, but breathe through gills on the sides of the head. They are cold-blooded animals; i. e., the temperature of the blood is the same as that of the water in which they are living. Fishes are found in both fresh and salt water all over the world and have adapted themselves to many conditions; for example, certain fishes have lived in caves so long that they are blind; some live in the coldest water, while others can revel in the heat of the hot springs.

[Ill.u.s.tration: COMMON CATFISH

The barbels which suggest the whiskers of a cat are responsible for the name. This fish has no scales. Range: Eastern and Central United States.]

Many fishes are valuable as food and the fisheries are extensive industries, in which large sums of money are invested.

There are four great groups of fishes:

1. The sharks and rays, with cartilaginous skeletons.

2. The ganoids of which the sturgeon and garpike are examples, with heavy plates or scales.

3. The bony fishes--salmon, pickerel, mackerel, cod, halibut, etc.

4. The lung fishes, that live partly in air.

[Ill.u.s.tration: SHOVEL-NOSED STURGEON

This fish is covered with bony plates instead of scales. The roe is made into caviar. _Range_: Upper and middle Mississippi Valley.]

There are many species of sharks. Among the more common ones in Atlantic waters are the Smooth Dogfish which have pavement-like teeth; the Sand Shark with catlike teeth; the Hammerhead Shark with its eyes on stalks.

The near relatives of the sharks are the Skates. The most common example of the ganoid fish is the sturgeon, which is heavily clad with a bony armor. Most of the fishes that we find, however, belong to the third group, i. e., bony fishes. Among the salt-water species, the cod, the halibut, the mackerel, and the bluefish are especially valuable as food. Of the salt-water fishes that go up the rivers into fresh water to breed, the salmon and the shad are widely known. Of a strictly fresh-water fish, the sunfish and catfish are very common. Among the game-fish are the trout, ba.s.s, pickerel, and salmon.

For those who live in cities, a convenient place to begin the study of fishes is in the fish-market. Here we may learn to know the common food-fishes by name, and to know many interesting things about them. If there is a Public Aquarium or a Natural History Museum in your city, you can use it in connection with the fish-market. Especially valuable in Museums are the habitat groups of fishes, that is, those in which the fishes are shown in their natural surroundings. But, best of all, the place to study fishes, as is true of all other animals, is out-of-doors in their native haunts. With your dip-net or hook and line, catch the fish, and then by the aid of one of the books listed below find out what its name is. Then, by observation of the fish see what is interesting in its life-history. Find out where the mother-fish lays her eggs. Does either parents guard them? Has the fish any natural weapons of defense?

If so, what are they? Does either parent care for the young after they are hatched? What does the fish feed upon? In what way is the fish protectively colored? In the study of fishes, an interesting means is the home aquarium. Any Girl Scout can easily learn how to install and maintain a balanced aquarium, that is, one in which the water does not have to be changed and in fact should not be changed. In such an aquarium one may keep and study a great variety of fishes. Some of our local fishes, such as young catfish and suckers, will prove fully as interesting as the goldfish and many other animals besides fishes will thrive in a small aquarium, such as tadpoles of frogs, toads, and salamanders, adult water-newts, soft-sh.e.l.led turtles, snails, and water-beetles and nymphs of dragon-flies.

[Ill.u.s.tration: HAMMERHEAD SHARK

The eyes are on the ends of blunt stalks, or extensions of the sides of the head, which suggest the name. Range: All warm seas, north to Cape Cod.]

[Ill.u.s.tration: A GARDEN UNDER WATER

Starfishes, Crabs and Sea-anemones]

[Ill.u.s.tration: SQUID

Member of same family as Octopus, and is related to the Oyster. Has ink bag for protection.]

Animals Without Backbones

In general the Invertebrates are animals without a backbone; that is, they do not have an internal supporting skeleton of bone, as does the dog or cat. Compared with mammals or birds, they are all small and some are so very tiny that they can be seen only with a very powerful microscope. Most of them live in the water or in the mud or sand under the water. Hence the best place to get acquainted with them is along the seash.o.r.e or near some lake or stream.

There are several different groups of Invertebrates and between these groups there are greater differences of structure than there is between a horse and a hummingbird. The princ.i.p.al groups are:

1. The Protozoa, or one-celled animals (nearly all microscopic).

2. The Sponges.

3. The Jellyfishes, Sea-anemones, and Corals.

4. Worms of several groups.

5. Starfishes, Sea-urchins, and Sea-cuc.u.mbers.

6. Segmented Worms.

7. Crabs, Lobsters, etc.

8. Oysters, Snails, and Octopi.

9. Insects and Spiders.

[Ill.u.s.tration: SNAILS AND THEIR TRACKS ON THE BEACH

--_Photograph by Mary C. d.i.c.kerson._]

Seash.o.r.e Life

Because of their connection with our industries or our food supply, some of the Invertebrates are familiar to all; for instance, sponges, corals, starfishes, crabs, shrimps, lobsters, clams, and oysters. Others are seldom seen unless one takes pains to look for them.

[Ill.u.s.tration: JELLY FISH]

All life comes from pre-existing life. So every animal living to-day has come from some other living animal and every plant living to-day has come from some other previously living plant. It is believed that the first forms of life came from the water. At any rate, the oldest and lowest forms of life to-day, the Protozoa, are found in the water. As these are nearly all very minute and can be studied only with a microscope, they are omitted from the suggested field work.

[Ill.u.s.tration: ANIMALS OF THE WHARF-PILES