SELF-POLLINATION 55 
dragged over the stigma and effect self-pollination in 
that way; it has nothing to do with the fall of the 
grains. Movement, of one sort or another, quite 
independent of gravity, is a very common device for 
self-pollination, and, as a matter of fact, in the Ragged 
Robin and the Convolvulus, too, self-pollination 
depends, in the last instance, not upon the fall of the 
grains, which is only a preliminary step, but upon the 
action of the stigmas in the one and of the corolla 
in the other. 
But there are other plants in which it is neither the 
stigmas that grow, nor the corolla that moves, but 
the stamens at last touch the stigma, and that very 
common pest, the Chickweed, is one of them. The 
flower is small, so it will be necessary to use a lens in 
order to make it out. We can, however, see the same 
thing quite plainly and unmistakably in some of the 
Lilies which are commonly grown in our gardens. 
In the Turk’s Cap and the White Lily the stamens, 
when the blossom first opens, are a long way from the 
stigma, but before it withers we often find that one 
of them has moved forwards, with the result that its 
pollen-laden anther lies right upon the sticky stigma, 
and this brings us to one of the most interesting of all 
the methods of self-pollination. 
The Wood-sorrel is one of the daintiest of our 
spring blossoms, or we may turn to the Sweet Violet, 
the Wood Violet, or the White Deadnettle, for in all 
of them, and in some other plants as well, there are 
two kinds of flower. 
There is the one that everybody knows and sees; 
but the other never gets beyond the stage of a tiny 
bud, nevertheless it performs the essential duty of a 
flower, which is, of course, to produce seeds. 
