By the autumn of the same year (1869) the self-fertilised plant which had been victorious was now beaten. The measurements are shown in Table 5/59.
TABLE 5/59. Pot 2.--Sarothamnus scoparius.
Heights of plants measured in inches.
Column 1: Crossed Plants.
Column 2: Self-fertilised Plants.
: 15 6/8 : 13 1/8. : 9 6/8 : 3. : 8 2/8 : 2 4/8.
The same plants were again measured in the autumn of the following year, 1870.
TABLE 5/60. Pot 2.--Sarothamnus scoparius.
Heights of plants measured in inches.
Column 1: Crossed Plants.
Column 2: Self-fertilised Plants.
: 26 2/8 : 14 2/8. : 16 4/8 : 11 4/8. : 14 : 9 6/8.
Total : 56.75 : 35.50.
The three crossed plants now averaged 18.91, and the three self-fertilised 11.83 inches in height; or as 100 to 63. The three crossed plants in Pot 1, as already shown, had beaten the three self-fertilised plants so completely, that any comparison between them was superfluous.
The winter of 1870-1871 was severe. In the spring the three crossed plants in Pot 2 had not even the tips of their shoots in the least injured, whereas all three self-fertilised plants were killed half-way down to the ground; and this shows how much more tender they were. In consequence not one of these latter plants bore a single flower during the ensuing summer of 1871, whilst all three crossed plants flowered.
Ononis minutissima.
This plant, of which seeds were sent me from North Italy, produces, besides the ordinary papilionaceous flowers, minute, imperfect, closed or cleistogene flowers, which can never be cross-fertilised, but are highly self-fertile. Some of the perfect flowers were crossed with pollen from a distinct plant, and six capsules thus produced yielded on an average 3.66 seeds, with a maximum of five in one. Twelve perfect flowers were marked and allowed to fertilise themselves spontaneously under a net, and they yielded eight capsules, containing on an average 2.38 seeds, with a maximum of three seeds in one. So that the crossed and self-fertilised capsules from the perfect flowers yielded seeds in the proportion of 100 to 65. Fifty-three capsules produced by the cleistogene flowers contained on an average 4.1 seeds, so that these were the most productive of all; and the seeds themselves looked finer even than those from the crossed perfect flowers.
The seeds from the crossed perfect flowers and from the self-fertilised cleistogene flowers were allowed to germinate on sand; but unfortunately only two pairs germinated at the same time. These were planted on the opposite sides of the same pot, which was kept in the greenhouse. In the summer of the same year, when the seedlings were about 4 1/2 inches in height, the two lots were equal. In the autumn of the following year (1868) the two crossed plants were of exactly the same height, namely, 11 4/8 inches, and the two self-fertilised plants 12 6/8 and 7 2/8 inches; so that one of the self-fertilised exceeded considerably in height all the others. By the autumn of 1869 the two crossed plants had acquired the supremacy; their height being 16 4/8 and 15 1/8, whilst that of the two self-fertilised plants was 14 5/8 and 11 4/8 inches.
By the autumn of 1870, the heights were as follows:--
TABLE 5/61. Ononis minutissima.
Heights of plants measured in inches.
Column 1: Crossed Plants.
Column 2: Self-fertilised Plants.
: 20 3/8 : 17 4/8. : 19 2/8 : 17 2/8.
Total : 39.63 : 34.75.
So that the mean height of the two crossed plants was 19.81, and that of the two self-fertilised 17.37 inches; or as 100 to 88. It should be remembered that the two lots were at first equal in height; that one of the self-fertilised plants then had the advantage, the two crossed plants being at last victorious.]
SUMMARY ON THE LEGUMINOSAE.
Six genera in this family were experimented on, and the results are in some respects remarkable. The crossed plants of the two species of Lupinus were conspicuously superior to the self-fertilised plants in height and fertility; and when grown under very unfavourable conditions, in vigour.