1644 THE HUMAN SIDE OF PLANTS 
plants, require sleep before they grow and blossom. 
And the more highly developed the plant, the more 
sleep it requires before coming forth. The small 
shrub does not need as much rest as the giant 
trees of the California forests. Think of the tre- 
mendous amount of work to supply food materials 
to the millions of delicate leaves of the upper 
branches of a gigantic redwood, towering over 
three hundred feet in the air! Even the evergreens, 
such as the pines and cedars, which seem to work 
all the year round, have their times for rest and 
recuperation. 
In this habit of vacational rests and regular 
sleep, plant life shows but another of its human 
traits. From the most lowly to the most mighty, 
all plants wake and slumber, slumber and wake, 
with methodical regularity, in response to the de- 
mands of nature. 
