one alone did the crossed show any marked superiority in height over the
self-fertilised; in four of the trials they were approximately equal;
and in one (i.e., in the first generation) the self-fertilised plants
were greatly superior to the crossed. In no case did the capsules from
flowers fertilised with pollen from a distinct plant yield many more,
and sometimes they yielded much fewer seeds than the capsules from
self-fertilised flowers. But when the flowers of one variety were
crossed with pollen from a slightly different variety, which had grown
under somewhat different conditions,--that is, by a fresh stock,--the
seedlings derived from this cross exceeded in height and weight those
from the self-fertilised flowers in an extraordinary degree.

Twelve flowers on some plants of the common tobacco, raised from
purchased seeds, were crossed with pollen from a distinct plant of the
same lot, and these produced ten capsules. Twelve flowers on the same
plants were fertilised with their own pollen, and produced eleven
capsules. The seeds in the ten crossed capsules weighed 31.7 grains,
whilst those in ten of the self-fertilised capsules weighed 47.67
grains; or as 100 to 150. The much greater productiveness of the
self-fertilised than of the crossed capsules can hardly be attributed to
chance, as all the capsules of both lots were very fine and healthy
ones.

The seeds were placed on sand, and several pairs in an equal state of
germination were planted on the opposite sides of three pots. The
remaining seeds were thickly sown on the two sides of Pot 4, so that the
plants in this pot were much crowded. The tallest plant on each side of
each pot was measured. Whilst the plants were quite young the four
tallest crossed plants averaged 7.87 inches, and the four tallest
self-fertilised 14.87 inches in height; or as 100 to 189. The heights at