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Show 296 PERIOD OF FLOWERING OF CnAr. vrrr. A consideration of the two :first lists, especially of the second one, shows that a tendency to flower first is generally connected with greater power of growth that • • • c. ' IS, With greater height. But there arc so1ne ren1arkahle exceptions to this rule, proving that some other canse comes into play. Thus the crossed plants Loth of Lupinus lute,us and Clarkia ele,qans were to the selffertilised plants in height as 100 to '82, and yet the latter flowered :first. In the third. generation of Nicotiana, and in all three generations of Canna., the crossed and self-£ rtilisod plants were of nearly equal height, yet the self-fertilised tended to flower first. 0~ the other hand, with P rinnda sinensis, plants ra1sed from a cross between two distinct in(1ividuals, whether these wer.e legitimately or illegitimately crossed, flowered before tho illegitimately self-fertilised pl~nts, .although all the plants were of nearly equal height In both cases. So it was with respect to height and flowering with Phaseolus, Specularia, and Borago. The crossed plants of Hibiscus were inferior in height to the self-fertilised, in the ratio of 100 to 109 ' and yet ,; they flowered before the self-fertilised in throe out of the four pots. On tho w hol , there can ·Lo no doubt that the crossed plants exhiLit a tendency to flower before the self-fertilised, ahnost though not quite so str?ngly marked as to grow to a greater height, to weigh Inore, and to be n1ore fertile. A few other cases not included in tho above throe lists deserve notice. In all three pots of Viola tricolor, naturally crossed plants the offspring of crossecl plants flowered before naturally crossed plnnts tho offspring of self-fertilised plants. )j' lowers on two plnnts, Loth of self-fertilised parentage, of tho sixth generation of Mi'lnulus luteus were intercrosse<l aud other flowers on the sa1ne plants were fertilised w' ith their own pollen; CnAr. VIII. CROSSED AND SELF-FERTILISED PLANTS. 297 intercrossed seedlings and seedlings of the seventh self-fertilised generation were thus raised, and the latter flowered before the intercrossed in throe out of the five pots. Flowers on a plant both of Mimulus luteus and of Ipomma purpurea were crossed \vith pollen from other flowers on the same plant, and other flowers were fertilised with their own pollen; intercrossed seedlings of this peculiar kind, and others strictly selffertilised being thus raised. In the case of the Mimulus the self-fertilised plants flowered. first in seven out of the eight pots, and in the case of the Ipomcea in eight out of the ten pots ; so that an intercross between the flowers on the same plant was very far from giving to the offspring thus raised, any advantage over the strictly self-fertilised plants in their period of flowering. The Effects of crossing Flowers on the same Plant. In the discussion on the results of a cross with a fresh stock, given under Table 0 in the last chapter, it was shown that the mere act of crossing by itself does no good; but that the advantages thus derived depend on the plants which are crossed, either consisting of distinct varieties which will almost certainly differ somewhat in constitution, or on the progenitors of the plants which are crossed, though identical in every external character, having been subjected to somewhat different conditions and having thus acquired some slight difference . in constitution. All the flowers produced by the same plant have been developed from the same seed ; those which expand at the same time have been exposed to exactly tho same climatic influences · and the stmns have all been nourished by the same ro' ots. Therefore in accordance with the con-clusion just referred to, no good ought to Tesult from |