TABLE 5/72. Nemophila insignis; 0 means that the plant died.
Heights of plants measured in inches.
Column 1: Number (Name) of Pot.
Column 2: Crossed Plants.
Column 3: Self-fertilised Plants.
Pot 1 : 32 4/8 : 21 2/8.
Pot 2 : 34 4/8 : 23 5/8.
Pot 3 : 33 1/8 : 19. Pot 3 : 22 2/8 : 7 2/8. Pot 3 : 29 : 17 4/8.
Pot 4 : 35 4/8 : 10 4/8. Pot 4 : 33 4/8 : 27.
Pot 5 : 35 : 0. Pot 5 : 38 : 18 3/8. Pot 5 : 36 : 20 4/8. Pot 5 : 37 4/8 : 34. Pot 5 : 32 4/8 : 0.
Total : 399.38 : 199.00.
The twelve crossed plants now averaged 33.28, and the ten self-fertilised 19.9 inches in height, or as 100 to 60; so that they differed somewhat less than before.
The plants in Pots 3 and 5 were placed under a net in the greenhouse, two of the crossed plants in the latter pot being pulled up on account of the death of two of the self-fertilised; so that altogether six crossed and six self-fertilised plants were left to fertilise themselves spontaneously. The pots were rather small, and the plants did not produce many capsules. The small size of the self-fertilised plants will largely account for the fewness of the capsules which they produced. The six crossed plants bore 105, and the six self-fertilised only 30 capsules; or as 100 to 29.
The self-fertilised seeds thus obtained from the crossed and self-fertilised plants, after germinating on sand, were planted on the opposite sides of four small pots, and treated as before. But many of the plants were unhealthy, and their heights were so unequal--some on both sides being five times as tall as the others--that the averages deduced from the measurements in Table 5/73 are not in the least trustworthy. Nevertheless I have felt bound to give them, as they are opposed to my general conclusions.
The seven self-fertilised plants from the crossed plants here average 15.73, and the seven self-fertilised from the self-fertilised 21 inches in height; or as 100 to 133. Strictly analogous experiments with Viola tricolor and Lathyrus odoratus gave a very different result.
TABLE 5/73. Nemophila insignis.
Heights of plants measured in inches.
Column 1: Number (Name) of Pot.
Column 2: Self-fertilised Plants from Crossed Plants.
Column 3: Self-fertilised Plants from Self-fertilised Plants.
Pot 1 : 27 : 27 4/8. Pot 1 : 14 : 34 2/8.
Pot 2 : 17 6/8 : 23. Pot 2 : 24 4/8 : 32.
Pot 3 : 16 : 7.
Pot 4 : 5 3/8 : 7 2/8. Pot 4 : 5 4/8 : 16.
Total : 110.13 : 147.00.
23. BORAGINACEAE.--Borago officinalis.
This plant is frequented by a greater number of bees than any other one which I have observed. It is strongly proterandrous (H. Muller 'Befruchtung' etc. page 267), and the flowers can hardly fail to be cross-fertilised; but should this not occur, they are capable of self-fertilisation to a limited extent, as some pollen long remains within the anthers, and is apt to fall on the mature stigma. In the year 1863 I covered up a plant, and examined thirty-five flowers, of which only twelve yielded any seeds; whereas of thirty-five flowers on an exposed plant growing close by, all with the exception of two yielded seeds. The covered-up plant, however, produced altogether twenty-five spontaneously self-fertilised seeds; the exposed plant producing fifty-five seeds, the product, no doubt, of cross-fertilisation.
In the year 1868 eighteen flowers on a protected plant were crossed with pollen from a distinct plant, but only seven of these produced fruit; and I suspect that I applied pollen to many of the stigmas before they were mature. These fruits contained on an average 2 seeds, with a maximum in one of three seeds. Twenty-four spontaneously self-fertilised fruits were produced by the same plant, and these contained on an average 1.2 seeds, with a maximum of two in one fruit. So that the fruits from the artificially crossed flowers yielded seeds compared with those from the spontaneously self-fertilised flowers, in the ratio of 100 to 60.