Outlines of Lessons in Botany, Part I; from Seed to Leaf eBook

This eBook from the Gutenberg Project consists of approximately 96 pages of information about Outlines of Lessons in Botany, Part I; from Seed to Leaf.
Lilac that the scales are modified leaves, and follow the leaf-arrangement of the species.  The Beech is alternate-leaved, and we should therefore expect the scales to alternate.  The explanation is found as we go on removing the scales.  At the eighth or ninth pair we come upon a tiny, silky leaf, directly between the pair of scales, and, removing these, another larger leaf, opposite the first but higher up on the rudimentary stem, and so on, with the rest of the bud.  There are five or more leaves, each placed between a pair of scales.  Our knowledge of the parts of a leaf shows us at once that the scales must be modified stipules, and that therefore they must be in pairs.[1] Other examples of scales homologous with stipules are the American Elm, Tulip-tree, Poplar and Magnolia.  The leaves are plaited on the veins and covered with long, silky hairs.  The venation is very distinct.  The outer leaves are smaller and, on examining the branch, it will be seen that their internodes do not make so large a growth as the leaves in the centre of the bud.

[Footnote 1:  See the stipules of the Pea, p. 31.]

[Illustration:  FIG. 15.—­Copper Beech. 1.  Branch in winter state:  a, leaf-scar; b, bud-scar. 2.  Branch, with leaf-buds expanding, showing the plicate folding of the leaves.]

The leaf-scars are small, soon becoming merely ridges running half round the stem.

The bud-rings are very plain and easily counted.  For this reason, and because it branches freely, it is a good tree for measurements of growth, as is seen in the following tables.  Nos. 1, 2, 3 and 4:  were made by a class of girls, from fourteen to sixteen, from a tree on my lawn.  No. 5 was made by a pupil, whom I taught by correspondence, from a tree of the same species in another town.  No. 6 was made by myself from my own tree.  The measurements of the first four tables were somewhat revised by me, as they were not perfectly accurate.  The pupils should always be cautioned to measure from the beginning of one set of rings to the beginning of the next.[1]

[Footnote 1:  Care must be taken to select branches well exposed to the light.  Of course there are many circumstances that may aid or hinder the growth of any particular branch.]

NO. 1.

---- in. ’79 8-1/2 —­ —­ —­ —­ ’80 4-1/2 2 1-7/8 —­ —­ ’81 3-1/2 1-1/8 2-5/8 —­ —­ ’82 6 5/8 4-1/4 5-7/8 —­ ’83 7-3/8 3-3/8 5-1/4 4 5-3/4 ’84 2 1/2 3/4 3/8 5-3/8 ’85 5/8 1/4 3/8 1/2 1 ’86 5-5/8 7/8 4-3/8 3-1/8 5

NO. 2.

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Outlines of Lessons in Botany, Part I; from Seed to Leaf from Project Gutenberg. Public domain.
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