stock, which had grown under different conditions.

[Several flowers on the crossed plants of the ninth generation in Table
2/10, were crossed with pollen from another crossed plant of the same
lot. The seedlings thus raised formed the tenth intercrossed generation,
and I will call them the "INTERCROSSED PLANTS." Several other flowers on
the same crossed plants of the ninth generation were fertilised (not
having been castrated) with pollen taken from plants of the same
variety, but belonging to a distinct family, which had been grown in a
distant garden at Colchester, and therefore under somewhat different
conditions. The capsules produced by this cross contained, to my
surprise, fewer and lighter seeds than did the capsules of the
intercrossed plants; but this, I think, must have been accidental. The
seedlings raised from them I will call the "COLCHESTER-CROSSED." The two
lots of seeds, after germinating on sand, were planted in the usual
manner on the opposite sides of five pots, and the remaining seeds,
whether or not in a state of germination, were thickly sown on the
opposite sides of a very large pot, Number 6 in Table 2/13. In three of
the six pots, after the young plants had twined a short way up their
sticks, one of the Colchester-crossed plants was much taller than any
one of the intercrossed plants on the opposite side of the same pot; and
in the three other pots somewhat taller. I should state that two of the
Colchester-crossed plants in Pot 4, when about two-thirds grown, became
much diseased, and were, together with their intercrossed opponents,
rejected. The remaining nineteen plants, when almost fully grown, were
measured, with the following result:

TABLE 2/13. Ipomoea purpurea.

Heights of Plants in inches: