CHAPTER V. 
Stems. 
‘57. What the Stem ts.—The work of nourishing the 
plant is done mainly by the roots and the leaves. The stem 
is that part or organ of the plant which serves to bring roots 
and leaves into communication with each other. In most 
flowering plants the stem also serves the important purpose 
of lifting the leaves up into the sunlight, where alone they 
best can do their especial work. 
The student has already, in Chapter II, learned some- 
thing of the development of the stem and the seedling; 
he has now to study the external appearance and internal 
structure of the mature stem. Much in regard to these can 
conveniently be learned from the examination of twigs and 
branches of our common forest trees in their winter condition. 
* 58. The Horse-Chestnut Twig.1— Procure a twig of horse-chestnut 
eighteen inches or more in length. Make a careful sketch of it, trying to 
bring out the following points : 
(1) The general character of the bark. 
(2) The large leaf-scars (marking the places where the bases of leaf- 
stalks were attached) and the number and position of the dots on these 
scars. : 
(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. 
See Fig. 23, 0 sc. 
(4) The buds at the upper margin of each leaf-scar and the strong 
terminal bud at the end of the twig. 
“1Where the buckeye is more readily obtained it will do very well. Hickory 
twigs answer the same purpose, and the latter is a more typical form, having alter- 
nate buds. The magnolia or the tulip tree will do. The student should (sooner or 
later) examine at least one opposite and one alternate-leaved twig. 
* 2 A very vigorous shoot may not show any such ring. 
