On The Origin of Species by Charles Darwin Chapter 4 Page 58

many other flowers on the same plant; and the pollen of each flower readily gets on its stigma without insect agency; for I have found that plants carefully protected from insects produce the full number of pods.

How, then, comes it that such a vast number of the seedlings are mongrelized? It must arise from the pollen of a distinct VARIETY having a prepotent effect over the flower’s own pollen; and that this is part of the general law of good being derived from the intercrossing of distinct individuals of the same species. When distinct SPECIES are crossed the case is reversed, for a plant’s own pollen is always prepotent over foreign pollen; but to this subject we shall return in a future chapter.

In the case of a large tree covered with innumerable flowers, it may be