And now what is a winter bud? It is a miniature shoot or flower, resting for the time, and snugly wrapped for the long winter. It was made last season. It is ready to leap into growth the moment the warm rain of spring wakens it. A good hand lens will show the embryo branch, if a section is made of the bud. This bud is not only ready-formed but is ready-fed. The winter shoots contain starch. On a cut surface of a dormant twig, apply a drop of tincture of iodine; note the bluish color, which is indicative of starch. This starch is insoluble; but with the first awakening of life, it changes into sugar, which is soluble and is transferred to the growing part. The burst of spring is made possible by means of this stored food. Notice the azalea in the florist's window (Fig. 230). The large flower-buds were formed the year before, and it is a short operation to "force" them into bloom. The flowers come in advance of the leaves; therefore these leaves could not have made the food required for the bloom. The blooming of the apple twig (Fig. 224) in the winter shows that the food is in the twig and buds. Once I drew a branch of a tree into a room and fastened it there. It made leaves and began to grow while the tree to which it was attached was perfectly dormant (Fig. 231). [Illustration: _Fig. 230. Bloom of azalea._] * * * * * [Illustration: _Fig. 229. The opening of a pussy willow._] Not only are the buds ready-formed and ready-fed, but they are covered. Snugly is the tender, growing part protected. Pull away the scales of a winter bud one by one. Observe how closely they are placed. Often the chinks are filled with a packing of wool, or are sealed with varnish. Dip the bud in water: then see whether the water permeates the covering. The chief value of the bud covering is not to protect from freezing, as commonly supposed, but to prevent the soft growing parts from drying out. The plants are waiting for spring. They are ready. [Illustration: _Fig. 231. Branch of a tree bearing leaves inside a window, when the tree itself is dormant._] LEAFLET XXXIII. EVERGREENS AND HOW THEY SHED THEIR LEAVES.[45] BY H. P. GOULD. [45] Teacher's Leaflet No. 13, February, 1899. [Sidenote: _Note to the teacher._--This leaflet has two particular objects: to teach how evergreens shed their leaves, and to enable you to distinguish a few of the evergreens which are most commonly met. These studies (and those suggested in Leaflet No. XXIX) should be the means of adding much cheer to the winter. Encourage pupils to make collections of cones, to observe when they shed their seeds, and how long (how many seasons) they remain attached to the branch. Remember that mere identification of the kinds of trees is not the highest type of nature-study.