, they had the same soil and moisture, the same sun and air, and the
same care. The plants that grew from these two sets of seeds were very
different, those from the self-fertilized seeds being smaller and weaker
in every way than those from the seeds fertilized with pollen from
another plant, or cross-fertilized, as we say, thus proving that it is
not best for the plant to be self-fertilized. Someway, it needs the
stimulus from less closely related pollen in order to grow vigorously
and perfectly.

While the cross-fertilization of the same order of plants is so
desirable, it is not possible for the pollen of one order to fertilize
the ovules of another order. There must be a certain degree of
similarity between flowers able to fertilize each other. The pollen of
an apple blossom might, for instance, rest upon the stigma of a lily,
but the pollen could not penetrate to the lily ovule. It would have no
effect upon the lily.

That the seed inherits equally from the ovule and the pollen grain is a
truth that should be impressed in many ways. It is very wonderful that
anything so small as a pollen grain, often as small as the tiniest speck
of dust, should be able to transmit to the young seed the peculiarities
of the plant from which it came. That it does this, the child himself
can prove in a most interesting way. He can plant some white petunia
seeds in one side of his garden, and some red ones in the other. The
seeds should come from a reliable florist's in order to be sure of
results. When the petunias ripen their seeds, those from the white
flowers should be gathered and carefully labelled, and then those of the
red flowers, care being taken not to mix the two colors. The next
summer, plant the seeds as before. When the flowers blossom, those in
the white bed will no longer be white,--some may be, but others will be
red, and still others red and white. The same will be true of the
flowers in the red bed. What has happened? The bees going from flower to
flower have carried the pollen from one bed to the other, and some of
it, rubbing off on the stigmas as the bees searched for honey,
fertilized the flowers. Thus some of the ovules of the white flowers
received an impression of red from the pollen of the red flowers, and
grew into red flowering plants. In others where the impression of red
was less strong, the result was the production of red-and-white spotted
flowers.

By fertilizing white flowers with pollen from re