A consideration of the two first lists, especially of the second one, shows that a tendency to flower first is generally connected with greater power of growth, that is, with greater height.  But there are some remarkable exceptions to this rule, proving that some other cause comes into play.  Thus the crossed plants both of Lupinus luteus and Clarkia elegans were to the self-fertilised plants in height as 100 to 82, and yet the latter flowered first.  In the third generation of Nicotiana, and in all three generations of Canna, the crossed and self-fertilised plants were of nearly equal height, yet the self-fertilised tended to flower first.  On the other hand, with Primula sinensis, plants raised from a cross between two distinct individuals, whether these were legitimately or illegitimately crossed, flowered before the illegitimately self-fertilised plants, although all the plants were of nearly equal height in both cases.  So it was with respect to height and flowering with Phaseolus, Specularia, and Borago.  The crossed plants of Hibiscus were inferior in height to the self-fertilised, in the ratio of 100 to 109, and yet they flowered before the self-fertilised in three out of the four pots.  On the whole, there can be no doubt that the crossed plants exhibit a tendency to flower before the self-fertilised, almost though not quite so strongly marked as to grow to a greater height, to weigh more, and to be more fertile.

A few other cases not included in the above three lists deserve notice.  In all three pots of Viola tricolor, naturally crossed plants the offspring of crossed plants flowered before naturally crossed plants the offspring of self-fertilised plants.  Flowers on two plants, both of self-fertilised parentage, of the sixth generation of Mimulus luteus were intercrossed, and other flowers on the same plants were fertilised with their own pollen; intercrossed seedlings and seedlings of the seventh self-fertilised generation were thus raised, and the latter flowered before the intercrossed in three out of the five pots.  Flowers on a plant both of Mimulus luteus and of Ipomoea purpurea were crossed with pollen from other flowers on the same plant, and other flowers were fertilised with their own pollen; intercrossed seedlings of this peculiar kind, and others strictly self-fertilised being thus raised.  In the case of the Mimulus the self-fertilised plants flowered first in seven out of the eight pots, and in the case of the Ipomoea in eight out of the ten pots; so that an intercross between the flowers on the same plant was very far from giving to the offspring thus raised, any advantage over the strictly self-fertilised plants in their period of flowering.

Effects of crossing flowers on the same plant.