50 ESSENTIALS OF BOTANY 
(2) The large horseshoe-shaped scars and the number and posi- 
tion of the dots on these scars. Compare a scar with the base of a 
leaf-stalk furnished by the teacher. 
(8) The ring of narrow scars around the stem in one or more 
places,! and the different appearance of the bark above and below 
such a ring. Compare these scars with those left after removing the 
scales of a terminal bud. 
(4) The buds at the upper margin of each leaf-scar and the 
strong terminal bud at the end of the twig. 
(5) The flower-bud scar, a concave impression, to be found in the 
angle produced by the forking of two twigs, which form, with the 
branch from which they spring, a Y-shaped figure. 
(6) (On a branch larger than the twig handed round for indi- 
vidual study) the place of origin of the twigs on the branch. Make 
a separate sketch of this. 
The portion of stem which originally bore any pair of leaves is called 
a node, and the portions of stem between nodes are called internodes. 
Describe briefly in writing alongside the sketches any observed 
facts which the drawings do not show. 
If your twig was a crooked, rough-barked, and slow-growing one, 
exchange it for a smooth, vigorous one, and note the differences. 
Or if you sketched a quickly grown shoot, exchange for one of the 
other kind. 
Answer the following questions: 
(a) How many inches did your twig grow during the last summer? 
How many in the summer before ? 
How do you know? 
How many years old is the whole twig given you? 
(6) How were the leaves arranged on the twig? 
How many leaves were there? 
Were they all of the same size? 
(c) What has the mode of branching to do with the arrangement 
of the leaves? with the flower-bud scars? 
(d) The dots on the leaf-scars mark the position of the bundles 
of ducts and wood-cells which run from the wood of the branch 
through the leaf-stalk up into the leaf. 
A very vigorous shoot may not show any such ring. 
