Several single-flowered carnations were planted in good soil, and were all covered with a net.  Eight flowers were crossed with pollen from a distinct plant and yielded six capsules, containing on an average 88.6 seeds, with a maximum in one of 112 seeds.  Eight other flowers were self-fertilised in the manner above described, and yielded seven capsules containing on an average 82 seeds, with a maximum in one of 112 seeds.  So that there was very little difference in the number of seeds produced by cross-fertilisation and self-fertilisation, namely, as 100 to 92.  As these plants were covered by a net, they produced spontaneously only a few capsules containing any seeds, and these few may perhaps be attributed to the action of Thrips and other minute insects which haunt the flowers.  A large majority of the spontaneously self-fertilised capsules produced by several plants contained no seeds, or only a single one.  Excluding these latter capsules, I counted the seeds in eighteen of the finest ones, and these contained on an average 18 seeds.  One of the plants was spontaneously self-fertile in a higher degree than any of the others.  On another occasion a single covered-up plant produced spontaneously eighteen capsules, but only two of these contained any seed, namely 10 and 15.

Crossed and self-fertilised plants of the first generation.

The many seeds obtained from the above crossed and artificially self-fertilised flowers were sown out of doors, and two large beds of seedlings, closely adjoining one another, thus raised.  This was the first plant on which I experimented, and I had not then formed any regular scheme of operation.  When the two lots were in full flower, I measured roughly a large number of plants but record only that the crossed were on an average fully 4 inches taller than the self-fertilised.  Judging from subsequent measurements, we may assume that the crossed plants were about 28 inches, and the self-fertilised about 24 inches in height; and this will give us a ratio of 100 to 86.  Out of a large number of plants, four of the crossed ones flowered before any one of the self-fertilised plants.

Thirty flowers on these crossed plants of the first generation were again crossed with pollen from a distinct plant of the same lot, and yielded twenty-nine capsules, containing on an average 55.62 seeds, with a maximum in one of 110 seeds.

Thirty flowers on the self-fertilised plants were again self-fertilised; eight of them with pollen from the same flower, and the remainder with pollen from another flower on the same plant; and these produced twenty-two capsules, containing on an average 35.95 seeds, with a maximum in one of sixty-one seeds.  We thus see, judging by the number of seeds per capsule, that the crossed plants again crossed were more productive than the self-fertilised again self-fertilised, in the ratio of 100 to 65.  Both the crossed and self-fertilised plants, from having grown much crowded in the two beds, produced less fine capsules and fewer seeds than did their parents.