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Show 270 CONCLUDING REMARKS CHAP. VI. TABLE 37. Nature of the Offspring from Ille,qitimately f ertilised TrimorJlhic Plants. Number Number Number of Long- of Mid- of Short· styled styled styled Offspring. Offspring. Offsp ring. ---- - ---- rong-styled form, fertilised Lythrum salicaria. by own-form pollen, pro-l 56 0 0 duced • • • • . . rhort-styled form, fertilised I • by own-form pollen, pro- 1 0 8 " " duced • • • • . . rhort-styled form, fel·tilised} by pollen from mid-length 4 0 8 " " · stamens of long- styled form, produced . . . {Mid-styled form, fertilised by} 1 3 0 " " • own-form pollen, produced {Mid-styled form, fertilised by} pollen from shortest sta- 17 8 0 " " • mem: of long-styled form, produced • • • • . {Mid-sty led form, fertilised by J pollen from longest st a- 14 18 " " · mens of short-styled form, produced • . . . . rong-styled form, fertilised) during several generations I Oxalis rvsea • by own-form pollen, pro- 100 0 0 duced offspring in the ratio of • • • . • " h d . d {Mid-sty led form, fertilised by} e ysaroi es own-form pollen, produced 0 17 0 - CHAP. VI. ON HETEROSTYLED PLANTS. 271 We see in these two tables that the offspring from a form illegitimately fertilised with pollen from another plant of the same form belong, with a few exceptions, to the same form as their parents. For instance, out of 162 seedlings from long-styled plants of Primula veris fertilised during :fi. ve generations in this manner, 156 were long-styled and only 6 shortstyled. Of 69 seedlings fro1n P. v~u~qaris similarly raised all were long-styled. So it was with 56 seedlings from the long-stylod form of the trimorphic Lythrum salicaria, and with numerous seedlings fro1n the longsty led form of Oxalis rosea. The offspring from the short-sty led forms of dimorphic plants, and from both the mid -sty led and short-sty led forms of trimorphic plants, fertilised with their own-form pollen, likewise tend to belong to the same form as their parents, but not in so marked a manner as in the case of the longstyled form. There are three cases in Table 37, in which a form of Lythrum was fertilised illegitimately with pollen from another form; and in two of these cases all t.he offspring belonged to the same two forms as their parents, whilst in the third case they belonged to all three forms. The cases hitherto given relate to illegitimate unions, but Hildebrand, Fritz Muller, and n1yself found that a very large proportion, or all of the offspring, from a. legitimate union between any two fonns of the trimorphic species of Oxalis belonged to the same two forms. A similar rule therefore holds good with unions which are fully fertile, as with those of an illegitimate nature . which are more or less sterile. When some of the seedlings from a heterosty led plant belong to a different form from that of its parents, I-Iildebrand accounts for the fact by reversion. For instance, the long-styled parent-plant of Primula. veris, from which |