AMERICAN HOMES AND GARDENS 
September, 1909 
Tobacco plants close under the hot sun of noonday 
plant which, as every one knows, shrinks from a touch. 
Moreover, it folds itself up in exactly the same way, and 
without being touched, at the approach of dusk. In common 
with many other plants, such as the clovers, it ‘‘goes to sleep” 
by folding its leaves and drooping its stems. But although 
we may speak of this phenomenon as ‘“‘sleep,” we are not 
justified in regarding it as identical with the slumber of 
animals. As far as an opinion can be formed on the subject, 
plants may be said not to need rest—at least during their 
period of active growth. So that, when we speak of a plant’s 
sleep, we must not assume that its nutritive processes are 
suspended at this time. ‘The plant is probably just as much 
awake as it is in the daytime. ‘The folding up of its leaves 
is an ingenious arrangement for resisting the fall in tem- 
perature which commences at sundown. It is just as though 
the plant turned up its collar and buttoned its coat more 
closely round it preparatory to a night’s watch; for scien- 
tific observation goes to prove that it preserves a normally 
active power of assimilation during its period of so-called 
sleep.’ 
In speaking of the movements of plants, we have, of 
necessity, to take very much of what we see for granted. 
For example, in numerous instances we are able to realize 
that a flower opens or closes at exactly the right time to 
promote—if one may use the expression—its own interests; 
but what influences induce this opening or shutting it seems 
difficult to determine, if we deny to plants all sensible knowl- 
edge of their surroundings. : 
Let us, in conclusion, examine a case or two in point. Take 
first the beautiful white water-lily. During the hours of sun- 
light its blossom lies flat upon the surface of the water, its 
wonderful chalice fully expanded, and its array of golden 
stamens exposed to view. But as dusk approaches the 
flower’s petals begin to close, and the flower itself sinks 
slowly beneath the surface of the water. 
work is over, and it has gone to rest. 
Some would explain this movement by saying that flowers 
are extremely sensitive to the effects of light and the ab- 
The lily’s day’s 
On the approach of dusk the flowers open wide 
sence of light. But if we grant this, how are we to explain 
the absolutely opposite behavior of other flowers? ‘Take 
the case of the tobacco plant flowers. At high noon, when 
the sun is hot and powerful, each bloom hangs its head with 
folded petals. But as the evening shadows fall the flowers 
seem to shake themselves from slumber, rise up, and expand 
into beautiful white stars, which shine conspicuously in the 
dusk long after the red and blue and purple blossoms have 
faded from sight. 
Doubtless the true explanation of the phenomena is that 
while the insect helpers which secure cross-pollination for 
the water-lily are day-flyers, those which perform the like 
ofices for the tobacco flowers are crepuscular or nocturnal. 
In this connection a somewhat remarkable fact was recently 
pointed out by a well-known writer on horticultural sub- 
jects, namely, that the newly produced tobacco: flowers of 
bright color seem to have already adopted the habit of 
remaining open during the daylight and closing at night. 
Now as colored flowers are acknowledged to be of little use 
as lures for night-flying moths, this is precisely the reasonable 
course for these colored nicotianas to pursue. But how came 
they to realize this unless, indeed, they are vested with 
some power equivalent to that which we term ‘“‘the power 
of thought?” 
Considerations of space forbid us to dwell longer upon 
this fascinating subject. We have seen something, however, 
of the ways in which vegetables surmount difficulties and 
achieve successes; and whether we regard these manifestations 
as the outcome of actual volition, such as is exercised by the 
higher animals, or as directly promoted by the immeasurable 
intelligence which we believe governs all animate and in. 
animate things, the issue is scarcely affected. Plants may 
not think; they may not of themselves pursue one course of 
action to the exclusion of another. Yet each incident of 
their existence bears witness to the fact that they are con- 
trolled by the same omniscient intellect which governs the 
activities, not merely of the lower animals, but even of man 
himself. 
