ANNUAL MEETING. 161 



state ready for unfolding wlien growth begins. By the degree of advance- 

 ment, or the preparation made during tlie previous year for growth, we may 

 foretell whether a tree will start and complete its annual growtli early or late 

 in the summer. 



Let us look at some young branches of a white oak tree. At this time of 

 year some of the dead leaves still remain attached wlicre they grew. The 

 strongest buds are towards the extremity of a branch. Near the end are three, 

 four or five quite near each otiier. By looking back at the growth of 1881, 

 we see old leaf scars. In some cases the buds developed this year into 

 branches; in other cases the old bud still remains as a bud or has fallen off. 

 During 1882, three or five buds near the end of a branch developed, making 

 something like a whorl of branches. Where the bud scales fell off they left 

 scars which somewhat resemble the wrinkles of a cows horn. The growths 

 made during different years, when all seen at one time, not only differ in size, 

 but tlie bark differs in color and some of its markings. It is quite easy by 

 these signs to tell the age of a branch. In many cases, especially where 

 branches are of slow growth as where they are much shaded by others above 

 them, it is possible to count the growth made each year back for twenty or 

 thirty years or more. 



We have seen that all the branches alike consist of nodes or joints where we 

 find one or more leaves with one or more buds just above each. These nodes 

 are a little way apart on the stem, and the space intervening between any two 

 contiguous nodes is called an internode. By watching the development of a 

 young tree we shall see that it is composed entirely of nodes and internodes. 

 An internode with the node at its apex, bearing one or more leaves, in the 

 axile of whicli is one or more buds, is called a phytomer. It is here illustrated. 

 We saw that the first or lower phytomer of the seedling developed roots at the 

 lower extremity. The place where the seed leaves come up is the first node of 

 the plant. 



It is not unusual for any part of some stems to put forth roots. This is 

 seen in Indian corn, poison ivy, and in some other plants. In one sense, a tree 

 is a very monotonous affair, being made up of a multitude of elements, all 

 essentially alike. 



As is well known, a tree cannot grow without leaves. These are put forth 

 every year, and are a contrivance for vastly increasing the surface. 



Au oak tree of good size exposes several acres of surface to the air during 

 the growing season. It has been estimated that the Washington elm, at Cam- 

 bridge, Massachusetts, not a very large tree, exposes about five acres of foliage, 

 if we include both sides of the leaves. 



Leaves are more nearly comparable to stomachs than to lungs. 



A leaf is a laboratory for assimilating or manufacturing raw materials into 

 plant fabric. The cellular structui'e of the leaves, wood, and bark of a tree, 

 is too complicated a subject to be satisfactorily presented to a popular audience. 



It requires a vast surface of leaves to do a little work. By counting the 

 leaves on a seedling oak and estimating the surface on both sides of eacli, we 

 can see liow many inches are needed to build up' the roots and stem for the 

 first year. After the first year the old stem of the oak bears no leaves. It is 

 dependent on the leaves of the branches, or its children, for support. A tree 

 is a sort of community, eacli part having its own duties to perform. The root 

 hairs take up most of the nourishment; the young roots take this to the 

 larger ones, and they in turn, like the branches of a river, pour the flood of 

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