“Yes; they do live in sea water. In order to grow and thrive they must have vegetable and mineral substances found in sea water. But they can live in fresh water. Oystermen make a practice of moving them from their banks to spots near the mouth of a river where the water is not nearly so salty or even quite fresh. Here they get washed out and freshened. They look plumper and some of the strong, salty taste being taken away, they have a more delicate flavor. All the largest oysters in the market are fattened in that way.” Willis did as directed. “Do you notice how the oyster is covered?” asked his aunt. “Yes, it has two shells which are joined like a hinge at the smaller end.” “Do you notice that they are different?” “One shell is larger and deeper near the hinge. The outside of it is white and pretty. The shelly matter is laid in rings, some of which seem full, making me think of a tucked and ruffled skirt. The other shell is smaller, darker and nearly flat.” “Ask Bridget if she has some small crackers to give you one. Powder it and throw it on top of the water. If she has none a spoonful of corn meal will do for food. Animals which are deprived of natural ways of getting a living must be supplied with suitable food.” When he had done that she handed him a pair of shells, in one of which lay an oyster. “Here is another one which I had opened for you. I am very busy to-day. While the company is here you can amuse yourself by watching what happens. Examine the dead oyster and find out what you can about it.” Willis was delighted with his odd pet. He watched the live creature for some time. At first its two shells were tightly closed. After being quiet for some time it cautiously opened its shell a little way as though it was peeping at him. He was so pleased that he grabbed his hat and ran to fetch his neighbor schoolmate, Joseph. Once in a while a bit of cracker would be drawn between the shells and, in time, disappear. The two boys were very much interested. “Let us look at the dead oyster, Willis.” “All right.” Taking a toothpick in his hand he tried to turn over the oyster in the shell. He found that a thickened muscle near the middle part was fastened to the half shell. Tearing it loose he saw at this place a dark, purplish spot just like one on the other half shell. “I wonder what makes that hard spot?” “Oh, see, Joseph! Its body has two sides. The side lying in the deeper piece of shell is larger. Down the middle is a division and the edges come together something like the cover of a book. Over all is a white covering with such pretty frilled edges. See, I can roll it back quite a little way.” “That is so. How pretty it is. It has no head. Does it eat? I wonder if it has a mouth.” Willis searched carefully for an opening. At last he found one near the hinge. “What is this?” asked Willis, handing his playmate a little doubled-up thing about as large as a pea.