SUNLIGHT FACTORIES 
47 
mile. Vines have one disadvantage. If they do 
not find a support, they cannot get their leaves 
into the light and as a result, they do not thrive 
so well. Climbing plants sometimes put on so 
many leaves that they shade the tree or bush 
they are leaning upon and injure it, and some¬ 
times even kill it by keeping the sunshine away. 
Plants are like people in a great many re¬ 
spects, but in one way they are much more 
independent, for they can make their own food. 
Each plant, big and small, is a busy food 
factory, and the busiest workshop in the factory 
is the leaf. Whenever you see green leaves on a 
tree you may know that they are working hard 
at manufacturing food that will keep the tree 
alive and make it grow tall and strong. Let us 
take, for example, an oak leaf and see what 
happens in its workshop. 
The first thing the leaf needs is water, and 
the veins which you have often noticed bring 
that. The water gets into the trees through the 
roots. It travels up the tree trunk through long 
narrow tubes which are connected to the veins. 
Morning 
glories must 
have a support 
How do plants 
get their food? 
