Examine an oyster from which the flat shell has been removed. Has it any bones? How is its body protected? Observe the thin membrane (mantle) covering the oyster; its fringed edges form the gills. Find on either shell a blue spot showing where the muscle is attached that opens and closes the shell; also the dark spot on the oyster where the liver is.

How The Oyster Lives

Oysters, clams, mussels, and scallops are salt-water shell-fish belonging to the family of mollusks, or soft-bodied animals. Their shells, built up of mineral matter secreted by the mantle, form a sort of outside skeleton. The young oyster floats about, but as its shell grows thicker and heavier, it settles down on the sand or rocks, the half shell, or valve, on which it lies becoming rounder and deeper than the one that covers it. The oyster has neither head nor limbs, but has a mouth near the hinge-end of its shell, and two strong muscles, one to open the shell to take in food and water, the other to close it, if a starfish or other enemy comes by. Oysters grow crowded together, forming oyster-beds.

Like fish, oysters are cultivated. Baby-oysters, called "seed-oysters," are planted all along the Atlantic coast. Oysters are not good for food when spawning. They spawn in summer, but not all at one time. It is customary, however, not to eat them during warm weather.

Great quantities of oysters are canned, especially for use in the West and Middle West.

Experiment

Boil a little oyster liquor. What forms on top? What foodstuff do oysters evidently contain? At what temperature, and for about what length of time, would you cook them?

Preparation Of Oysters

Oysters are commonly opened by the fish-dealer. To clean oysters, drain off the liquor, straining it through a wire strainer if it is to be used. Rinse the oysters on a colander, using only half a cupful of cold water to one quart of oysters, to avoid washing away the flavor. With the fingers examine the gills to see that no bits of shell are left clinging to them.

How To Serve Raw Oysters

Oysters are served raw with lemon as a first course at luncheon or dinner. Horse-radish sauce or ketchup may be served with them. Arrange six oysters "on the half shell," on crushed ice on each plate, with the small ends toward the centre. Place a quarter of a lemon in the middle of the circle.

Oysters As Food

Oysters contain as much water as milk does. Like milk, and unlike most other animal foods, they contain, besides protein, fat, and mineral matter, considerable carbohydrate.1 Oysters are more or less salt according to the saltness of the water they grow in. Their fuel value is little more than two-thirds that of milk. As they commonly cost five times as much as milk, they are an expensive food. (See charts 3 and 6.)

After being dredged up, oysters are often floated in shallow water for a day or two to free them from dirt and slime. This cleansing should be done in pure water about as salt as that they came from. If put into fresher water, they absorb it, swell up, and lose much of their salts and with these their flavor. People have contracted typhoid fever by eating oysters either grown or floated in water contaminated by sewage.

Oyster Stew

Stewing oysters, 1 p. Hot milk, 1 c.

Butter, 2 tb. Salt.

Pepper, f. g.

Drain and rinse the oysters, strain the liquor, and heat the oysters in it till their edges curl,2 remove the scum, and turn oysters and liquid into the hot milk. Add butter and seasoning. Serve with oyster crackers.

Scalloped Oysters

Oysters, 1 pt., solid. Melted butter, 1/2 c. Stale bread crumbs, 2 c.

Salt, about 1 t. Pepper, 1/4 t. or more. Oyster liquor, or oyster liquor and milk, 5 or 6 tb.

1 Glycogen, in the liver, which in the oyster is comparatively large (P. 142).

2 If cooked longer, they will be leathery.

Mix the crumbs with the salt, pepper, and butter; spread one-third of them on the bottom of a buttered baking-dish; put in half of the oysters, drained and rinsed, another layer of crumbs, and the rest of the oysters; and cover the top with the remaining crumbs. Pour over these the liquid. Bake about twenty minutes in an oven hot enough to brown the crumbs in that time.

A grating of nutmeg or a slight sprinkling of mace may follow each layer, if you choose.

Other Shell-Fish

Lobsters, crabs, and shrimps are crustaceans; that is, animals consisting of jointed sections, each of which is covered with a hard shell. Their flesh is similar in composition to that of other fish, but tough and hard to digest. It is liked because of its unique and delicate flavor.

Brief Reference List

For further development of topics treated in this section see: -

Sherman: Food products. Ch. 7.

Ward : Grocer's encyclopedia. (Articles on fish, fish-culture, and under separate headings, cod, crabs, etc.) U. S. Dept. of Agriculture : Farmers' bulletin: 85. Fish as food. U. S. Dept. of Agriculture : Bureau of Chemistry. Bulletin 133.

Preparation of cod and other salt fish for the market. Illust. Bigelow: Applied biology. P. 358, Lobsters and other crustaceans; p. 405, Oysters and other mollusks. Smith: Oysters. National geographic magazine, v. 24, no. 3, March, 1913.