142 HETEROSTYLED TRIMORPHIC PLANTS. CHAP. IV. 



thers. The end of the pistil is generally bent upwards 

 at right angles. The six longest stamens, with their 

 pink filaments and green pollen, resemble the corre- 

 sponding stamens of the mid-styled form. But accord- 

 ing to H. Miiller, their pollen-grains are a little larger, 

 viz. 9^-1 0|, instead of 9-10 in diameter. The six 

 mid-length stamens, with their uncoloured filaments 

 and yellow pollen, resemble in the size of their pollen- 

 grains and in all other respects the corresponding 

 stamens of the long-styled form. The difference in 

 diameter between the grains from the two sets of 

 anthers in the short-styled form is as 100 to 73. 

 The capsules contain fewer seeds on an average than 

 those of either of the preceding forms, namely, 83.5; 

 and the seeds are considerably smaller. In this latter 

 respect, but not in number, there is a gradation 

 parallel to that in the length of the pistil, the long- 

 styled having the largest seeds, the mid-styled the 

 next in size, and the short-styled the smallest. 



We thus see that this plant exists under three 

 female forms, which differ in the length and curva- 

 ture of the style, in the size and state of the stigma, 

 and in the number and size of the seed. There are 

 altogether thirty-six males or stamens, and these can 

 be divided into three sets of a dozen each, differing 

 from one another in length, curvature, and colour of 

 the filaments, in the size of the anthers, and especially 

 in the colour and diameter of the pollen-grains. Each 

 form bears half-a-dozen of one kind of stamens and 

 half-a-dozen of another kind, but not all three kinds. 

 The three kinds of stamens correspond in length with 

 the three pistils: the correspondence is always between 

 half of the stamens in two of the forms with the pistil 

 of the third form. The following table of the diameters 

 of the pollen-grains, after immersion in water, from 



