The Walnut seed flowers (6) are so small that they require to be looked for carefully. They grow among the leaves at the end of the twig, and their small seed-vessels, each with a closely-fitting calyx covering, are ready before the leaves come out. Very soon the small seeds develop into smooth green fruits, which continue to grow all summer, and in July they are the size of a small plum. This fruit is a nut (7), the famous Walnut, and at first you will not see in it any likeness to the Walnut which we eat at dessert after cracking the pale brown shell. But look more closely. The green fruit is a soft juicy envelope which conceals a large nut. This green envelope turns brown when it is ripe and splits open, showing the nut inside, a nut with a crinkled skin, which is soft and green at first, but which becomes a hard, pale brown shell when the fruit dries. It is the kernel of this nut which we eat with salt as a dessert fruit. The Walnuts usually ripen in October, but often they are gathered in July before the juicy green covering has turned brown, and they are preserved in vinegar and used as a pickle. Ripe Walnuts contain a great deal of oil, and the oil is much valued by artists, who mix it with their paints. It is the most liquid of all the oils, and it dries very quickly. If you look at your fingers after gathering Walnuts you will find that they are stained a dark brown. The Walnut tree contains a juice which leaves a dark stain. It is said that with this juice the gipsies dye their skin brown; and it is also used to stain floors. Walnut wood is very valuable. It is light in weight and dark in colour, with beautiful veins and streaks throughout. Much fine furniture is made of Walnut wood, and it can be polished till it shines like satin. To-day it is largely used in the manufacture of guns and rifles. You will now understand what an important tree the Walnut is, as it yields fruit and oil and wood, which are all valuable. PLATE XXX THE SWEET CHESTNUT OR SPANISH CHESTNUT The Sweet Chestnut is a cousin of the Oak, and belongs with it to the great family of cup-bearing trees, or those that bear their fruit sitting in a cup. Like the Oak, it is a tree with a great and ancient history, although nowadays we are apt to take little notice of this tree, which was once well known and grew abundantly in many parts of England. The largest Chestnut in the world grows in Sicily, in the great forest which covers the slopes of Mount Etna. It is said that a Spanish Queen was once overtaken in this forest by a tremendous storm, and that she and a hundred soldiers and horses were all able to find shelter beneath the wide-spreading branches of this one tree. In this country we have a famous big Chestnut tree in Gloucestershire which is believed to be a thousand years old; it is written about in old books, which tell us that this tree belonged to a certain house in the time of King Stephen. [Illustration: PLATE XXX THE SWEET CHESTNUT