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Show 226 ILLEGITIMATE OFFSPRING OF CHAP. Y. In this last case we have an instance of reversion in colour, without the possibility of any cross, to the grandparents or more distant progenitors of the plants in question. Altogether 23 plants in the first generation and 46 in the second generation were raised ; and the whole of these 69 illegiti1nate plai>rts weTe long-styled ! Eight. purple-flowered and two yellow-flowered plants of the first illegitimate generation were fertilised in various ways with their own pollen and with that of the common primrose ; and the seeds were separately counted, but as I could detect no difference in feTtility between the purple and yellow varieties, the results are run together in the following table. (See next page.) 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 illegitiInate 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 co1nn1on 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 fertilise.d with pollen from these illegitimate plants; and th1s 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 CHAP. V. HETEROSTYLED DIMORPHIC PLANTS. 227 TABLE 32. Primula vulgg,ris. Nature of Plant experimented on, and kind of Union. ~~ ~~ ~~ ~c~ jc~ 0 s ~ -g § 8. a.i ::;J ·- 0. ::;J .... P. ~ -~ Cli :.... z .;!l s z .;!l ~ z UJ ~ .... ~ ,.oP. '-'00 s~o '0 0 ~~ ~~ ~~0. ::l Jj ~ ~~~ z~ Z;E e~~ S:....o a ..... o .8 P. g: 0 ·~ 0 ~ :§ 0 ~ ~ (5 <lj ~~ ~~ Purple- and yellow-flowered illegi-J ~---------- timate long-styled plants, £lteg£- ~ timately fertilised with pollen I 72 11 11 · .'J 26 5 fro~ the same plant • • . / Purple- and yellow-flowered illegi-l j timate long-styled plants, iltegz'- tirnately fertilised with pollen! 72 from the common long-styled primrose. • • • • • . Or, if the ten poorest capsules} in~luding less than 15 seeds, b~ 72 reJected, we get. . . • . 39 62 3 40'6 r8 --------- --- '----------- PU1:ple- and yellow-flowered illegi-) I t~mate long-styled plants, legi-1 t~mately fertilised with pollen! 26 fr~m the common short-styled 18 36•4 60 9 pnmrose. • . • . . • reJ.e cted, we get. • • • ' . 26 r6 41 • 2 6o Or, if the two poorest capsules } including less than 15 seeds b~ ------------~----------- 1'he long-styled form of the commonl primrose, £lleq£timately fertilised ~ith. ~ollen from the long-styJedJ 20 Illegitimate purple- and yellowflowered plants . . • . . Or, if t~e three poorest capsules} be reJected, we get . • • . 20 - 14 II 15·4 46 1 r8·9 8 Thes~ort-styledformofthecommon) -----~---PI? mrose, legiUmately fertilised} ~1th pollen from the long-styled 10 6 30•5 61 6 Illegitimate purple- and yellow-flowered plants . . . • . - primrose produces a considerable number of capsules. There can, therefore, be no doubt that the fertility of Q 2 |