106 
WORLD OF INVISIBLE LIFE 
What is 
pollen? 
again. The little rootlet would burst out of the 
skin covering and fasten itself in the ground, 
the stem would raise up and the leaves pull out 
of the skin and at once begin to manufacture 
food. The food we saw in the leaf cells would 
be used up very rapidly in the first few days and 
even hours of the seedling’s growth, but by the 
time it is gone, the leaves are big enough to 
make their own food. 
In order to get a seed which can produce a 
new plant, it must first be fertilized. This is 
done by pollen . Pollen is the yellow or brown 
powder which we see in the hearts of flowers 
or in the catkins of poplar or willow trees. 
When the wind blows, this yellow dust is 
shaken from the flowers and falls on the imma¬ 
ture seeds and fertilizes them. 
When we look at a grain of pollen under the 
microscope, we see that it is a very tiny round 
or oblong cell with thick walls. The walls 
often have designs or bristles on them and some¬ 
times there are wings attached to them which 
act as sails. The cells are filled with protoplasm 
