Let us see how this castle is built. You have heard that wasps were the first paper makers. In the early summer you will see them around wood that has been worn by the weather. They take off loose fibres and by means of their mouth-parts work them into pulp. Can the rain get through this paper? Find out whether it is waterproof. Some of the nests made by vespa (Fig. 353), as the hornets or yellow-jackets are called, are very large. Do you think a wasp could make one alone? No, these are social wasps; that is, a great many live together. There are males, females, and workers. Some day we shall tell you how the wasps form their colony, but for this lesson we want you to study the nest. Notice the envelope which covers the cells. How many layers of paper are there in it? We might call each layer a clapboard. Can you see any difference in the direction of the outside layers on top of the nest and those which are below? [Illustration: _Fig. 354. Interior arrangement of white-faced hornet's nest._] How many stories high is the nest? Note the difference in the size of the stories. Where do you find the smallest? Count the rooms or cells in each. You know, of course, that an egg is placed in each cell. When the larvæ, as the young of the wasps are called, are hatched, they still live in the cells. How do they manage to keep in their cells? You see the nest is really turned upside down. Their little heads must hang where the worker wasps can feed them easily. I wonder whether you can tell me why the young wasps do not fall out? The workers chew all the food which they give the little ones. When in summer you see hornets about your flower beds or feeding on other insects, it may be that they are preparing breakfast for the young. Notice the flowers which they visit. POLISTES, THE PAPER-MAKER. In the previous lesson I spoke of vespa wasps that make homes of paper. You learned that they bite off pieces of weather-worn wood with their jaws and chew it until it is made into pulp. Were you interested in these social wasps? If so, you may like to hear about another member of the same family. [Illustration: _Fig. 355. Home of polistes, the paper-maker._] Hiding in some crevice about your house or the school building there is probably a wasp which naturalists call po-lis´-tes. She has been there ever since the cold weather came. In the spring you may see her tearing off pieces of wood from some unpainted building or weather-worn fence. Let us see what she is going to do. This wasp is the founder of a colony. The first thing she does is to select a place for her home. Then she makes a few cells--only a few, for she has no help. When you find a nest like the one in the picture (Fig. 355), you will see how the comb is fastened to the roof or to a tree or to the under side of a stone.