145 
Now, what part of a plant is usually best fitted to 
receive the sun’s rays? 
Psvicaves, to pe-sure., “The thin, fiat Jeat. blades are 
spread out on all sides, so that they fairly bathe them- 
selves in sunshine. 
So-t6 the broth isto: be cooked in the -sun;..up, to 
the leaves it must be carried. 
And how is this managed? Water does not run 
uphill, as you know. Yet this watery broth must 
mount the stem before it can enter the leaves. 
Water does not run uphill ordinarily, it is true; yet, 
if you dip a towel in a basin of water, the water rises 
along the threads, and the towel is wet far above the 
level of the basin. 
And if you dip the lower end of a lump of sugar 
mea cup ot -cottee, the coffee risés-in the lump,jand 
stains it brown. 
And the oil in the lamp mounts high into the wick. 
Perhaps when you are older you will be able some- 
what to understand the reason of this rise of liquid in 
the towel, in the lump of sugar, in the lamp wick. The 
same reason accounts partly for the rise of the broth 
in the stem. But it is thought that the force which 
sends the oil up the wick would not send the water 
far up the stem. And you know that some stems are 
very tall indeed. The distance, for example, to be 
traveled by water or broth which is sucked in by the 
roots of an oak tree, and which must reach the top- 
most leaves of the oak, is very great. 
Yet the earth broth seems to have no difficulty in 
making this long, steep climb. 
DANA’S PLANTS. — 10 
