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Show 140 HETEROSTYLED TRIMORPHIC PLANTS. CHAP. IV. . Lon,q-styled form.- This for~ _can ~e at once recognised by the length of the pistil, which is (includino· the ovarium) fully one-third longer than that of th~ mid-styled, and more than thrice as long as that of the short-styled form. It is so disproportionately long, that it projects in the bud through the folded petals. It stands out considerably beyond the mid-length stamens; its terminal portion depends a little, but the stigma itself is slightly upturned. The globular stigma is considerably larger than that of the other two forms, with the papillce on its surface generally longer. The six mid-length stamens project about two-thirds the length of the pistil, and correspond in length with the pistil of the mid-styled form. Such correspondence in this and the two following forms is generally very ?lose ; ~he difference, where there is any, being usually 1n a shght excess of length in the stainens. The six · shortest stamens lie concealed within the calyx ; their ends are .turned up, and they are graduated in length, so as to form a double row. The anthers of these stamens are smaller than those of the mid-length ones. The pollen is of the same yellow colour in both sets. H. Muller* measured the pollen-grain in all three forms, and his measurements are evidently more trustw? rthy than those which I formerly made, so I will give them. The numbers refer to divisions of the micrometer equalling s&o mm. The grains, distended with water, from the mid-length stainens are 7-7!, and those from the shortest stamens 6-6~ in diameter, or as 100 to 86. The capsules of this form contain on an average 93 seeds: how this average was obtained will presently be explained. As these seeds, when cleaned, seemed larger than those from the n1id- * 'Die Befruchtung der Blumen,' 1873, p. 193. 0HA1:'. IV. L Y'fHRUM SALICARIA. 141 ~ty led or short-sty led forms, 100 of them were placed ~n a good balance, and by the double method of w ighIng were found to equal121 seeds of the mid-styled or 142 of the short-styled; so that :five long-style l seeds very nearly equal six mid-styled or seven short-styled seeds. Mid-styled for?n.-The pistil occupi s th position represented in the diagram, with its extremity considerably upturned, but to a variable deo-ree; the . . b stigma IS seated between the anthers of the longest and the shortest stamens. The six lono·est stamens . b correspond 1n length with the pistil of the long-sty led form; their :filaments are coloured bright pink; the anthers are dark-coloured, but from containing brightgreen pollen and froin th ir early dehiscence they appear emerald-green. Hence in general appearanc these stamens are remarkably dissimilar from the mid-length stamens of the long-sty led form. The six shortest stamens are enclosed within the calyx, and resemble in all respects the shortest stamens of the long-Btyled form; both these sets correspond in length with the short pistil of the short-sty led form. The gr en pollen- grains of the longest stamens are 9-10 in diameter, whilst the yellow grains from the shortest stamens are only 6; or as 100 to 63. But the pollengrains from different plants appeared to m , in this case and others, to be in some degree variable in size. The capsules contain on an average 130 seeds; but perhaps, as we shall see, this is rather too high an average. The seeds themselves, as before remarked, are smaller than those of the long-sty led form. Short-styled form.-The pistil is h re very short, not one-third of the length of that of the long-styled form. It is enclosed within the calyx, which, differently from .. that in the other two forms, does not enclose any an- • |