THE LIFE OF A PRIMROSE. 
155 
other plant they contain a sticky substance with 
little grains in it. This substance is called "proto- 
plasm," or the first form of life, for it is alive and 
Fig- 39- 
Plant-cells. 
a, round cells in pith of elder. 
b, long cells in fibres of a plant. 
active, and under a 
microscope you may- 
see in a living plant 
streams of the little 
grains moving about 
in the cells. 
Now we are pre- 
pared to explain how 
our plant grows. Ima- 
gine the tiny primrose 
plantlet to be made up 
of cells rilled with 
active living proto- 
plasm, which drinks in 
starch and other food 
from the seed-leaves. 
In this way each cell will grow too full for its skin, 
and then the protoplasm divides into two parts 
and builds up a wall between them, and so one cell 
becomes two. Each of these two cells again breaks 
up into two more, and so the plant grows larger and 
larger, till by the time it has used up all the food in 
the seed-leaves, it has sent roots covered with fine 
hairs downwards into the earth, and a shoot with 
beginnings of leaves up into the air. 
Sometimes the seed-leaves themselves come above 
ground, as in the mustard-plant, and sometimes they 
are left empty behind, while the plantlet shoots 
through them. 
