HOW SOME FAMILIAR THINGS LOOK 103 
sprouts and grows, instead of growing from a 
seed as most new plants do. Many plants can 
produce new plants both ways. They have 
roots from which new plants sprout and they 
grow seeds from which new plants will grow. 
One of the most common of the plants which 
belong to the last group is the potato. 
The potato is a root. Its main object is to 
store food for the young plants which may de¬ 
velop from its eyes or buds. If we look at the 
soft juicy tissue of the inside of the potato under 
the microscope, we discover that it contains 
chiefly starch. Globes of the starch are stored 
in the many thin-walled cells of the potato. The 
globes themselves consist of innumerable layers, 
like those of an onion, around a solid center 
which is not in the middle of the grain but usu¬ 
ally near one end. Sometimes two or more 
grains grow together. When we want to see 
these thin layers more clearly, we stain the starch 
grain with iodine, which turns it blue. In many 
of the cells there is a little protoplasm and even 
a nucleus in addition to the starch grains. 
Potato with buds 
The potato is a root which 
contains starch 
How does the 
potato loo\? 
Starch grains 
