WORK DONE IN MAKING STARCH 119 
What use the plant makes of starch. Since starch is 
so necessary to plants, we ought to know some of the 
uses which the plant makes of it. It helps to make 
new life substance in the plant. This is necessary, not 
only because more life substance is needed as the plant 
becomes larger, but because, in one kind of work which 
the plant does, some of the life substance is consumed. 
We must understand that when the starch helps to form 
new life substance it no longer exists as starch but is 
assimilated along with other foods which the root takes 
up. Lhe making of starch is not the making of the life 
substance. Jt must be assimilated with the other food 
substances taken up by the root from the soil, or by the 
water plant from the water, before living material is 
made. 
When we eat solid food substances they are acted 
on by certain juices of the mouth, stomach, and other 
organs. A part of the food is thus digested and dis- 
solved. These food solutions are then absorbed through 
the surface of the large intestine, where they enter the 
blood. In the blood vessels they are finally carried to 
all parts of the body, where they come in contact with 
the living matter. The digested food is now assimilated 
piece of wood in water, and then set the vessel in the light. To show 
_ Clearly that land plants do the same kind of work which the water plants 
indicate by the bubble sign would be too difficult an experiment for 
young persons. | 
