* * * *

With respect to the benefit derived from crossing distinct varieties,
plenty of evidence has been published. Sageret[287] repeatedly speaks
in strong terms of the vigour of melons raised by crossing different
varieties, and adds that they are more easily fertilised than common
melons, and produce numerous good seed. Here follows the evidence of an
English gardener:[288] "I have this summer met with better success in
my cultivation of melons, in an unprotected state, from the seeds of
hybrids (_i.e._ mongrels) obtained by cross impregnation, than with old
varieties. The offspring of three different hybridisations (one more
especially, of which the parents were the two most dissimilar varieties
I could select) each yielded more ample and finer produce than any one
of between twenty and thirty established varieties."

Andrew Knight[289] believed that his seedlings from crossed varieties
of the apple exhibited increased vigour and luxuriance; and M.
Chevreul[290] alludes to the extreme vigour of some of the crossed
fruit-trees raised by Sageret.

By crossing reciprocally the tallest and shortest peas, Knight[291]
says, "I had in this experiment a striking instance of the stimulative
effects of crossing the breeds; for the smallest variety, whose height
rarely exceeded two feet, was increased to six feet; whilst the height
of the large and luxuriant kind was very little diminished." Mr. Laxton
gave me seed-peas produced from crosses between four distinct kinds;
and the plants thus raised were extraordinarily vigorous, being in each
case from one to two or three feet taller than the parent-forms growing
close alongside them.

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Wiegmann[292] made many crosses between several varieties of cabbage;
and he speaks with astonishment of the vigour and height of the
mongrels, which excited the amazement of all the gardeners who beheld
them. Mr. Chaundy raised a great number of mongrels by planting
together six distinct varieties of cabbage. These mongrels displayed an
infinite diversity of character; "But the most remarkable circumstance
was, that, while all the other cabbages and borecoles in the nursery
were destroyed by a severe winter, these hybrids were little injured,
and supplied the kitchen when there was no other cabbage to be had."

Mr. Maun