The sun. [volume] (New York [N.Y.]) 1916-1920, 1919-04-27

II Is, however. a mistake to suppose
that this rest of plants Is confined to
regions Of the earth where a cold sea-
son occurs: as matter Of fact, tropi-
cal plants have a season of rest also,
only with them 1t comes at the dry
period of the year.
1t is likely that the periodic rest of
plants may originally have been i'm
pressed upon plants in seasons of
drought and cold, but the fact remains
that many plants now rest when there
Is apparently no necessity to call Il
forth. kerner notes that in tropical
seas some species OF alga develop in
March, some i'll June, and some others
In October, though the conditions of
! light, temperature and moisture re-
main practically unchanged. Among
our wild plants there are many spe-
cies that rest in both summer and
winter. The spring beauty and the
adder's tongue enjoy a brief season OF
growth and bloom in early spring and
then vanish from view until another
vernal season calls them forth for n
short time. The crocus tulip. mar
cissus and other cultivated dubious
plants behave in the same manner.
Possibly the majority OF the crocuses
! vary the proceedings by Towering in
autumn Instead OF spring, resting in
winter. producing leaves and fruit in
spring and resting again in summer.
Our common wild leek has some
what similar habit. It produces its
leaves in spring. and In July, long after
ha IDrnt
Gus flower stalks push up out of the
soil. Even bacteria have resting
periods. when they form the so-called
spores by taking on a thicker cell wall
Other fungi form very characteristic
| winter spores called teleutospores.
That q period OF rest is In some way
necessary or mt least inherent in
plants is shown by the behavior of
! various species that store up food in
some underground part. Potatoes,
carrots, parsnips and other roots
stored In the cellar where the tenn
perature varies but little during tho
winter will not put out new shoots
until late In the season and those
plants which form their flower buds
late In autumn refuse to bloom in
December even when given plenty OF
warmth, but they win bloom readily
enough in the first mild days of early
spring when tho temperature and
other conditions seem much less IA
vorable. Annual plants commonly
pass through the winter in the form
| OF seeds, and though often scattered
at the beginning of summer remain
dormant through the warm weather
to spring up and grow vigorously in
the cool. moist days of spring. On
the other hand. tho seeds of plants
that are not easily harmed by the
cold of winter may grow as soon as
| ripe. Among these are the seeds of
cress, barley, mustard and many
weeds like the evening primrose,
prickly lettuce and shepherds purse.
In regions where wet and dry sea-
sons alternate ANIMALS ripen their
seeds before the dry season sets In
and these will not grow until another
wet season, through they may be mois-
tened by an occasional shower in the
meantime.
During the resting periods Of plants
the more obvious vegetable processes
are held in check, but some activity
within the plant may occur. During
winter some of the spring towering
plants make more or less root growth,
wounds callous over and foods are
moved on toward the terminal buds
Seeds also in many cases mellow and
ripen after gathering through various
chemical changes that occur. The diff
ference between new and old seeds
may often be told by the taste and
smell especially in the almond. beech
nut. hazelnut and chestnut. SINH
larly the favor of parsnips and oyster
plant is thought to improve when sub
Jected 20 the cold. and the chufe when
dried increases In sugar content. In
some cases the changes that go on In