26 STRUCTURE OF STEM. 
year; and at c. is the commencement of the one which 
will flower during the next year. In all these, the new 
buds feed on the nourishment which is deposited in 
the bulb, by the plant which has gone before. 
OF THE STRUCTURE OF THE STEM. 
25. When the young plant has risen above ground, 
it soon begins to take on all the forms which are 
peculiar to it as a plant; it lengthens, and gradually 
opens a few leaves; in process of time it throws out 
branches, if such is its nature; and at last expands its 
flowers, forms and ripens its seeds. But before all 
these latter parts of its structure can be produced, it 
has to perfect its stem as far as is necessary. Thus in 
the Lilac, which becomes a small tree, the first shoot 
is green and slender, this then buds some more new 
leaves, and commences at a later period to push out its 
branches; and in order that these branches may be 
able to have proper support, the stem grows with the 
whole plant, and at last attains a tolerable size. So 
that the part which is first formed, as the lower part 
of the stem, always keeps in advance of those parts 
which are formed at a later period. 
26. This will be made clearer by making an exami- 
nation of the structure of the stem, after the following 
manner. 
If the examination is made during the winter season, 
the smaller branches and twigs of the plants referred 
to, will serve to show the structure. Take a young 
shoot of the Lilac in leaf, or of any other shrubby 
plant, as the Hedge-rose, Elder, &c. cut it across, and 
