140 HETEROSTYLED TRIMORPHIC PLANTS. Ghap. IV. 



Long-styled form. — This form can be at once recog- 

 nised by the length of the pistil, which is (including 

 the ovarium) fully one-third longer than that of the 

 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 sta- 

 mens; 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 papillae 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 

 close; the difference, where there is any, being usually 

 in a slight excess of length in the stamens. 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 sta- 

 mens are smaller than those of the mid-length ones. 

 The pollen is of the same yellow colour in both sets. 

 H. Miiller* measured the pollen-grain in all three 

 forms, and his measurements are evidently more trust- 

 worthy than those which I formerly made, so I will 

 give them. The numbers refer to divisions of the 

 micrometer equalling ^ mm. The grains, distended 

 with water, from the mid-length stamens 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 ob- 

 tained will be presently explained. As these seeds, 

 when cleaned, seemed larger than those from the mid- 



* ■ Die Befruchtung der Blumen,' 1873, p. 193. 



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