How does the arrangement of the scales and leaves in the bud differ from that of the Horsechestnut? How are the leaves folded in the bud? What is the arrangement of the leaves on the stem? How does this differ from Horsechestnut and Lilac? How old is your branch? How old is each twig? What years were the best for growth? How does the growth of the branches differ from that of Horsechestnut? From Lilac? Explain these differences with reference to the growth and arrangement of the buds? In what direction do the twigs grow? How does this affect the appearance of the tree? Compare the amount of spray of the Beech and Horsechestnut and explain the reason of the difference. These questions are only intended for review, they are never to be used for the first study of the specimen. AMERICAN ELM (_Ulmus Americana_). The buds are covered with brown scales, which are hairy on the edges. The flower-buds are larger than the leaf-buds and are in the axils of the lower leaves of the preceding year. Each leaf in the bud is enclosed by a pair of scales. They are so small that the pupils, unused to delicate work, will hardly discover them. Under a glass they can be seen to be ovate, folded on the midrib with the inner face within (_conduplicate_), and with an ovate scale joined to the base of the leaf on either side. The scales thus show themselves to be modified stipules. The venation of the leaves is very plain. The scales are much larger than the leaves. The flower-buds contain a cluster of flowers, on slender green pedicels. The calyx is bell-shaped, unequal, and lobed. The stamens and pistil can be seen. The flower-clusters do not seem to leave any mark which is distinguishable from the leaf-scar. [Illustration: FIG. 16.--American Elm. 1. Branch in winter state: _a_, leaf-scars; _b_, bud-scars; _d_, leaf-buds; _e_, flower-buds. 2. Branch, with staminate flower-buds expanding. 3. Same, more advanced. 4. Branch, with pistillate flowers, the leaf-bud also expanding.] The leaf-scars are small and extend about half around the stem. The arrangement is alternate on the one-half plan. There are three dots on the scar. The rings are quite plain. The tree can be used to make tables of growth, like those of the Beech.