CHAP. IV. CROSSED AND SELF-FERTILISED PLANTS. 133 



Several single-flowered carnations were planted ;n 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, viz., as 

 100 to 92. As these plants were covered by a net, they pro- 

 duced 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 pro- 

 duced 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 



