Oxford Democrat. [volume] (Paris, Me.) 1833-1933, 1902-11-18
OUR
N AT v F.:
TREES
THCNAS H. MACBRIDE. Pm. D..
Professor Of Botany, Iosod Stotc
University.
1.-THE Fruits Of Trees.

1.-The FRUITS OF lreeS.
YN our northern woods all growth
is conditioned by our alternating
seasons. Growth in plants, as we
know, begins or is renewed In
spring and ceases at the approach Of
fall or winter. Renewal, apart now
from the agency Of seeds, comes about
in various ways-by tubers, bulbs, by
underground roots and stems. In the
tree the renewal results, first, from the
unfolding of buds formed in the axis
of last years leaves and all ready by
expansion to furnish the foliage and
twigs Of the season, and, second, from
the cambium and its associated living
tissues, described In the preceding
chapter. The buds contain at base and
throughout a very great number of IN
differentiated cells-like cambium cells,
in fact-capable Of growing SO as to
form different structures and organs
These carry forward the growth Of the
tree in height. The twigs stretch out
from buds. All development upward
takes origin in buds. In this respect,
however, the development OF bud on
q tree is different in nowise from the
unfolding Of the bud Of the meanest
weed stretching up to form Its eva
nescent stem. In all the higher plants
an length increase proceeds from buds.
But the second factor in the trees re-
newal is, as has been said. the peculiar
characteristic Of the tree, and to it we
must row again give heed.
In spring no sooner the buds begin
to swell and grow than the cambium
and its kindred tissues likewise re-
sumo activity. The cambium in par
ticular takes up its work just where 1t
stopped the fall before. but under very
different conditions. In autumn work
is suspended, often suddenly. in the
full tide of the trees activity. Ever
since June at least the foliage of the
tree has been doing fullest duty. The
roots have been equally vigorous. fur
nishing every active cell throughout
the tree abundant material with which
to build. The result is that the work
done by the tree in the later months of
summer is it's best work. Then 1t is
the cambium Is richest, builds more
bark and more wood. The wood also
is better. The cells are not only much
more numerous, but they are smaller.
and their walls are very much thick
err. Growing, as they do. under Il con
stantly strengthening sheath Of corti
cal tissues, the new wood cells are IN.
der ever increasing pressure. They
are in most cases closely compacted
together. There are no large vessels
such as in early spring were especially
needful to carry the vast amount of
water demanded by myriad forming
leaves. And now, when frost, shorten
ing days and other autumna condi
tons finally supervene. our tree is real
ly ut its best But the north wind
sounds retreat. The leaves fall; the
naked buds appear; the ground freezes:
the cambium rests. When spring re
turns, everything has changed. The
bark has been checked and loosened
nv the storms and frosts of winter.
The roots are fairly active, 1t is true.
often more or less completely protect
ed from the frost, but there are no
leaves to furnish forth supplies OF
food for any active cells. Resumed
activity depends for days entirely upon
supplies left over from tie year be-
fore, stored largely as starch. in the
twigs and at their bases and in the
medullary rays. to be further on de-