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Show 84 HETEROSTYLED DIMORPHIC PLANTS. CHAP. Ill. with the short-styled plants. The one w~ich grew dose to the long-styled plant pro~u?ed ninety.-four imperf ctly fertilised capsules containing a multitude of bad seeds, with a moderate number of good ones. The two other short-sty led plants growing together were small, being partly smothered by other plants; they did not stand very close to any long-styled plants, yet they yi lded together nineteen capsules. These facts seem to show that the short-styled plants are more fertile with their own pollen than are the long-styled, and we shall immediately see that this probably is the case. But I suspect that the difference in fertility betwc n the two forms was in this instance in part due to a distinct cause. I repeatedly watched the flowers, and only once saw a humble-bee mo1nentarily alight on one, and then fly away. If bees had visited the several plants, there cannot be a doubt that the four longstyled plants, which did not produce a single capsule, would have borne an abundance. But several times I saw small diptera sucking the flowers ; and these insects, though not visiting the flowers with anything like the regularity of bees, would carry a little pollen fi!Om one form to the other, especially when growing near together; and the stigmas of the short-styled plants, diverging within the tube of the corolla, would be more likely than the upright stigmas of the longstyled plants, to receive a small quantity of pollen if brought to them by small insects. Moreover from the greater number of the long-styled than of the shortstyled plants in the garden, the latter would be n1ore likely to receive pollen from the long-styled, than the long-sty 1 ed from the short-sty led. In 1862 I raised thirty-four plants of this Linum in a hot-bed; and these consisted of seventeen long-styled ~nd .seventeen short-styled forms. Seed sown later in the CHAP. II!. LINUM GRANDIFLORUM. 85 1 flower-garden yielded seventeen long-styled and twelve short-styled forms. These fact~ justify the statement that the two forms are produced in about equal num~ bers. The thirt!-four plants of the first lot were kept u~der a net wh1c~ excluded all insects, except such minute on~s.as Thnps. I fertilised fourteen long-style(} flowers legitimately with pollen from the short-styled, and got eleven fine seed-capsules, which contained on an average 8·6 seeds per capsule, but only 5·6 appeared to be go~d. It may be well to state that ten seeds is th.e maximum production for a capsule, ancl that our chmate cannot be very favourable to this North-African plant. On three occasions the stig1nas of nearly a hundred flowers were fertilised illegitimately with their own-form pollen, taken from separate plants, so as to ~rev en t anY possible ill effects from close inter-breed- 1ng. Many other flowers were also produced, which, as before stated1 must have received plenty of their own pollen; yet from all these flowers, borne by the seventeen long-sty led plants, only three capsules were produced. One of these included no seed, and the other two together gave only five good seeds. It is probable that this miserable product of two half-fertile capsules from the seventeen plants, each of which must have pro~uced .a~ least fifty or sixty flowers, resulted fron1 their fertihsa tion. with ~ollen from the short-sty led pl~nts b.y the ~Id of ~hrips ; for I made a great m.Istake ~n keeping the two forn1s under the san1e net, WI~~ theu branches often interlocking; and it is surpn~ Ing that a greater number of flowers were not acmden tally fertilised. Twelve short-sty led flowers were in this instance castrated, and afterwards fertilised legitimately with pollen from the long-styled form; and they produced seven fine capsules. ~rhese included on an average |