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Show 348 SELF-FERTILE VARIETIES. CIIAI>. IX. some t1. mes w1· th the individuals of thf e sa. me. spehc'i es. Soine allied cases of the appearance o vanet1es w 1c1 1, h If-fertilised yield more seed and produce off-w en se , f f .1. d spring growing taller than their sel - erti 1~~ parc~ts~ or than the intercrossed plants of the correspmHhng generation, will now be eonsidered. . Firstlv in the third and fourth generations of Mimulus" 'luteus a tall variety, often alluded to, having large ~hite flowers bl.otched with criinson, appeared amongst both t_he 1-r:tercrossed and selffertilised plants. It prevailed In _all the later selffertilised generations to the exclusion of _every other variety, and transmitted its characters fa1thfu~ly, bnt · disappeared from the intercrossed plants, owing no don bt to their characters being repeatedly blended by crossing. The self-fertilised plants belon~in g to this variety wer~ not only taller, but more fer.tile than t~e , intercrossed plants ; though these latter 1n tho earher generations were much taller and more fertile t~an the self-fertilised plants. Thus in the fifth gene1~atwn. the self-fertilised plants were to the intercrossed 1n height as 126 to 100. In the sixth generation they were likewise much taller and finer plants, but were not actually measured; they produced capsules compared with those on the in tercrossed plants, in n urn bor, as 14 7 to 100; and the self-fertilised capsules containe:l a greater number of seeds. In the seventh generatwn the self-fertilised plants were to the crossed in hei~ht as 137 to 100; and twenty flowers on these s~lf-fertilised plants fertilised with their own pollen !te~c~ed nineteen very fine capsnles,-a degree of self-fertiht! which I have not seen equalled I· n any ot h er. case. Tlus variety seems to have become specially ada pte~ to profit in every way by self-fertilisation, although th1s process was so l.1 1.J 1H.i ous to t h e parent -p l an t s dlli'l.I1g the first CHAP. IX. SELF-FERTILE VARIETIES. 349 four generations. It should however be remembered that seedlings raised from this variety, when crossed by a fr~~h stock, were wo~~erfully superior in height and fert1hty_to the self-fert1hsecl plants of the corresponding generation. Secondly, in the sixth self-fertilised generation of Ipomooa a single plant named the I-Iero appeared, which · exceeded by ~ little in height its intercrossed opponent, -a ca~e wh~ch had not occurred in any previous generation. Hero transmitted the peculiar colour of its flowei~s, as wei~ ~s its i~creased tallness and a high degree of self-fertility, to 1ts children, grandchildren, and great-grandchildren. The self-fertilised children of Hero were in height to other self-fertilised plants of the same stock as 100 to 85. Ten self-fertilised capsules produced by the grandchildren contained on an average 5 · 2 seeds; and this is a higher averao·e than was yielded in any other generation by the ca~sules of self-fertilised flowers. The great-grandchildren of Hero derived from a cross with a fresh stock were so unhealthy, from having been grown at an unfavourable season, that their average height in COinparison with that of the self-fertilised plants cannot be judged of with any safety; but it did not appear that they had profited even by a cross of this kind. · · Thirdly, the plants of Nicotiana on which I experimented appear to come under the present class of cases; for they varied in their sexual constitution and were more or less high! y self-fertile. They were probably the offspring of plants which had been spontaneously self-fertilised under glass for several generations in this country. The flowers on the parent-plants which were first fertilised by me with their own pollen yielded half again as many seeds as did |