But suppose it is winter time, and the tree is bare. Then you have a chance to see the wonderful framework of trunk and branches, the way the twigs spread apart on the outer limbs, while the great boughs near the trunk are almost bare. Each branch is trying to hold its twigs out into the sunshine, and each twig is set with buds. When these buds open, and most of them send out leafy shoots, the tree will be a shady summerhouse with a thick, leafy roof that the sun cannot look through. Among the big branches near the trunk very few leaves will be found compared with the number the outer twigs bear. How can we tell whether the tree is alive or dead in winter? Break off a twig. Is there a layer of green just inside the brown bark? This is the sign that the tree is alive. Dead twigs are withered, and their buds are not plump and bright. The green is gone from under the bark of these twigs. Under each bud is the scar of last year’s leaf, and if you look on the ground you are pretty sure to find a dead leaf whose stem fits exactly into that scar. If there are a number of these leaves under the tree, you may feel sure that they fell from the tree last autumn. Look carefully among the leaves, and on the branches for the seeds of this tree. If there is an acorn left on the tree, you may be sure that you have the tree’s name! The name is the thing we wish first to know when we meet a stranger. If an acorn is found growing on a tree, that tree has given us its name, for trees that bear acorns are all oaks. An acorn is a kind of nut, and there are many kinds of oaks, each with its own acorn pattern, unlike that of other oaks. Yet all acorns sit in their little acorn cups, and we do not confuse them with nuts of other trees. So we know the family name of all trees whose fruits are acorns. They are all oaks, and there are fifty kinds in our own country, growing wild in American forests. But if those of all countries are counted, there are in all more than three hundred kinds.