THE POLLEN. 159 
srowing many more plants of a similar description, 
it is necessary that certain processes should take 
place in the flower, which are very simple and 
interesting. If the little pieces we have called 
anthers are carefully examined, particularly if 
they are looked at through a small magnifying 
glass, they will be found to be sprinkled over 
with an immense number of very small grains, 
which to the eye look like so much yellow 
powder: this is called pollen. Before the little 
seeds placed in the ovary can be ripened or made 
fit to grow, it is necessary that these little yellow 
grains on the anthers should fall upon the piece 
called the stigma; and could we watch with the 
naked eye the events which take place, we should 
find that this actually comes to pass. After 
falling there the yellow pollen grains have been 
found to put forth a little tube each, which 
pierces the tender cells of the stigma, and then 
seems to enter into the seeds contained in the 
receptacle or ovary below. 
There are, however, many plants the flowers of 
which do not contain both stamens and a stigma. 
In these, the stamens are in one flower, and the 
stigma in another; and these may even grow on 
