XLV 
TREES INVENTED AIRPLANES 
I SN’T IT ODD that trees invented airplanes long be¬ 
fore man did! 
These airplanes are usually of the glider type, riding 
long distances on the wind without the use of power to 
drive them. 
The seed of the willow tree, for example, is so tiny that 
it can hardly be seen as it rides by on the wind, supported 
by a fluffy parachute and bearing a germ of life that may 
grow into a huge tree. 
The cottonwood tree, that borders the streams of the 
West and often furnishes shade for the settlers on the 
plains, is really a variety of poplar. Its seeds are put up 
in little pods, which burst open and release them with 
many tiny fibers attached, suggesting cotton. Sometimes 
the air is so full of these floating seeds that they become 
a nuisance. But the seeds get themselves broadcast for 
planting. 
The maple seeds spread wings which often grow to¬ 
gether in pairs for all the world like those of a bird, and 
the mother tree trusts to the wind to carry its babies away 
to a cradle that will hold them while they grow. The 
elm, the birch, and the ash launch ships that ride the 
wind. 
Many of these trees have their natural homes along the 
courses of streams. The streams are usually low at the 
time the seeds are taking flight. The seeds scatter them- 
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