Purple- and yellow-flowered illegitimate long-styled plants, ILLEGITIMATELY fertilised with pollen from the same plant : 72 : 11 : 11.5 : 26 : 5.
Purple- and yellow-flowered illegitimate long-styled plants, ILLEGITIMATELY fertilised with pollen from the common long-styled primrose : 72 : 39 : 31.4 : 62 : 3.
Or, if the ten poorest capsules, including less than 15 seeds, be rejected, we get: 72 : 29 : 40.6 : 62 : 18.
Purple- and yellow-flowered illegitimate long-styled plants, LEGITIMATELY fertilised with pollen from the common short-styled primrose : 26 : 18 : 36.4 : 60 : 9.
Or, if the two poorest capsules, including less than 15 seeds, be rejected, we get: 26 : 16 : 41.2 : 60 : 15.
The long-styled form of the common primrose ILLEGITIMATELY fertilised with pollen from the long-styled illegitimate purple- and yellow-flowered plants: 20 : 14 : 15.4 : 46 : 1.
Or, if the three poorest capsules be rejected, we get: 20 : 11 : 18.9 : 46 : 8.
The short-styled form of the common primrose LEGITIMATELY fertilised with pollen from the long-styled illegitimate purple- and yellow-flowered plants: 10 : 6 : 30.5 : 61 : 6.
If we compare the figures in this table with those given in the first chapter, showing the normal fertility of the common primrose, we shall see that the illegitimate purple- and yellow-flowered varieties are very sterile. For instance, 72 flowers were fertilised with their own pollen and produced only 11 good capsules; but by the standard they ought to have produced 48 capsules; and each of these ought to have contained on an average 52.2 seeds, instead of only 11.5 seeds. When these plants were illegitimately and legitimately fertilised with pollen from the common primrose, the average numbers were increased, but were far from attaining the normal standards. So it was when both forms of the common primrose were fertilised with pollen from these illegitimate plants; and this shows that their male as well as their female organs were in a deteriorated condition. The sterility of these plants was shown in another way, namely, by their not producing any capsules when the access of all insects (except such minute ones as Thrips) was prevented; for under these circumstances the common long-styled primrose produces a considerable number of capsules. There can, therefore, be no doubt that the fertility of these plants was greatly impaired. The loss is not correlated with the colour of the flower; and it was to ascertain this point that I made so many experiments. As the parent-plant growing in Edinburgh was found by Mr. Scott to be in a high degree sterile, it may have transmitted a similar tendency to its offspring, independently of their illegitimate birth. I am, however, inclined to attribute some weight to the illegitimacy of their descent, both from the analogy of other cases, and more especially from the fact that when the plants were LEGITIMATELY fertilised with pollen of the common primrose they yielded an average, as may be seen in the table, of only 5 more seeds than when ILLEGITIMATELY fertilised with the same pollen. Now we know that it is eminently characteristic of the illegitimate offspring of Primula Sinensis that they yield but few more seeds when legitimately fertilised than when fertilised with their own-form pollen.
Primula veris, Brit. Fl.
Var. officinalis of Linn., P. officinalis OF Jacq.
Seeds from the short-styled form of the cowslip fertilised with pollen from the same form germinate so badly that I raised from three successive sowings only fourteen plants, which consisted of nine short-styled and five long-styled plants. Hence the short-styled form of the cowslip, when self-fertilised, does not transmit the same form nearly so truly as does that of P. Sinensis. From the long-styled form, always fertilised with its own-form pollen, I raised in the first generation three long-styled plants,--from their seed 53 long-styled grandchildren,--from their seed 4 long-styled great-grandchildren,--from their seed 20 long-styled great-great-grandchildren,--and lastly, from their seed 8 long-styled and 2 short-styled great-great-great-grandchildren.