MANUAL OF NATURE STUDY. 
53 
also, that the leaves act as stomach and lungs to 
the plant. What takes place in our lungs? In 
our stomachs ? In the lungs and stomach of the 
plant ? 
As there must be a boarding house to feed the 
men who do the work in basket factory, or iron 
foundry, so must there be a boarding house to feed 
the helpers in the seed factory. Now the leaves 
constitute that boarding house. The sap is brought 
up by the stem, air and moisture through the mouths 
of the leaves, and all these elements are worked 
over by the sun into the choicest food. But these 
workers cannot leave their respective places to come 
to the boarding house for their meals, so the food 
must be sent to them in some way. Did you ever 
carry dinner to factory men? Well, that is what 
veins are for, to carry food, and this they do quite 
cheerfully. Food is in that way sent to the roots, 
for they have to eat in order to grow and do their 
work; to the stem, for it, too, has to work in car¬ 
rying water to the factory and sap to the leaves, 
hence it must eat; to the seed factory itself, be¬ 
cause it also must eat to develop seeds, and the 
leaves eat what is left after supplying all the others. 
Refreshments are sent in form of sugar to the seed 
factory and the seed factory works it over into starch 
and deposits it in the food part of the seed. Then, 
