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Show 218 ANAGALLIS COLLINA. CHAP. VI. took after their mother, and were red-coloured. But on two of the plants the flowers were plainly stained with blue, and to such a degree in one case as to be almost inter mediate in tint. The crossed seeds of the two foregoing , kinds and tho selffertilised were sown on the opposite sides of two lar()'e pots, and the seedli!!gs were measured when fully grown, as shown in tho two following tables:- TABLE XCII. Anagallis collina. Red Variety cro sed by a di stinct Plant of the Red Variety, . and Red Variety Self-fertilised; - - - - - -- No. of Pot. Crossed Plants. Self-fertilised Plants. --- -- --- Inches. Inches. I. 23g 15g ~1 1 5~ 17 ~ 14 I - Total in inch es. I 61·75 45 •00 Red Variety crossed by T3lue Variety, and Red Variety Self-fertili sed. No. of Pot. Cros ed Plants. Self-ferti li ed Plants. - Inches. I nches. II. 30g 24~ 27 ~ 1 8~ 25 11 ~ Total in inches. 82•88 54· 75 - Total of both lots. 144·63 I 99·75 As the plants of the two lots are few in number, they may be run together for the general average; ·but I may first state that the height of the seedlings from the cross between two individuals of tho red varjety is to that of tho self-fertilised plants of the red variety as 100 to 73; whereas the height of tho crossed offspring from the two varieties to tho self-fertilised plants of the rod varict.y is as 100 to 66. So that the cross between the two varieties is here seen to be the most advantageous. The average height of all six crossed plants in the two lots taken together is CHAP. VI. PRIMULA VERIS. 219 48·20, and that of the six self-fertilised plants 33· 25; or as 100 to 69. These six crossed plants produced spontaneously twenty-six capsules, whilst the six self-fertilised plants produced only two, or as 100 to 8. There is therefore the same extraordinary difference in fertility between the crossed and self-fertilised plants as in the last genus, Cyclamen, which belongs to the same family of the Primulaceoo. PRIMULA VERIS. Brit. Flora. ·c Var. officinalz:s, Linn.). The Cowslip. Most of the species in this genus are heterosty led or dimorphic; that is, they present two forms,-one long-styled with short stamens, and the other short-styled with long stamens.* For complete fertilisation it is necessary that pollen from the one form should be applied to the stigma of the other form; and this is effected under nature by insects. Such unions, and the seedlings raised from them, I have called legitimate. If one form is fertilised with pollen from the same form, the full complement of seed is not produced; and in the case of some heterostyled genera no seed at all is produced. Such unions, and, the seedlings raised from them, I have called illegitimate. These seedlings are often dwarfed and more or less sterile, like hybrids. I possessed some long-styled plants of P. ver-is, which during four successive generations had been produced from illegitimate unions between long-styled plants; they were, moreover, in some degree inter-related, and had been subjected all the time to similar conditions in pots in the greenhouse. As long as they were cultivated in this 1nanner, they grew well and were healthy and fertile. Their fertility even increased in the later generations, as if they were becoming habituated to illegitimate fertilisation. Plants of the first illegitimate gener9,tion when taken from the greenhouse and planted in moderately good soil out of doors grew well and were healthy; but when those of the two last illegitimate generations were thus treated they became exces- * See my paper ' On the Two Forms or Dimorphic Condition in the Species of Primulu,' in 'Journal of Proc. Linn. Soc.' vol. vi.l862, p. 77. A second pape1·, to which I presently refer, ' On the Hy bricl· like Nature of the Offspring from the Illeo-itimate Unions of Dimorphic and Trimorphic Plants,' was published in vol. x. 1867, p. 393, of the same journal. |
