170 MB. C. DABWIN ON" THE SEXUAL HET.ATIOXS OF 



mapliroJite being in its female organ quite distinct from the 

 other two hermaphrodites and partially distinct in its male 

 organs, and each furnished with two sets of males. 



The three forms may be conveniently called, from the unequal 

 lengths of their pistils, the long-stijled, mid-styled, and sJiort-styUd. 

 Their existence and diilereuces were first observed by Vaucher*, 

 and subsequently more carefully by Wirtgeu ; but, not being guided 

 by any theory, neither author perceived some of the most curious 

 points of difference. I will first briefly describe the three forms 

 by the aid of the accompanying accurate diagram, which shows 

 the flowers, six times magnified, in their natural position, with 

 their petals and the near side of the calyx removed. 



Long-styled form. — This can at once bo recognized 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 dispropor- 

 tionately long, comjiared with the flower, that it projects in 

 the bud through the unfolded petals. It stands out consi- 

 derably beyond the longer stamens ; its terminal portion de- 

 pends a little, but the stigma itself is slightly upturned : the 

 globular stigma is considerably larger than that of the other 

 two forms. The six longer stamens project about two-thirds 

 of the length of the pistil, and correspond in length with the 

 pistil of the mid-styled form. The correspondence with the 

 pistil in length in this and the two following cases is generally 

 very close ; the difference, where there is any, being usually in a 

 slight excess of length in the stamens. The six shorter stamens 

 (each of which alternates with a longer one) lie concealed within 

 the calyx ; their ends are upturned, and they are graduated in 

 length, so as to form a triple row — ^both which characters are 

 here much more marked than with the longer stamens, which 

 vary in these respects. The anthers of the shorter stamens are 

 smaller than those of the longer stamens. Knowing that the 

 pollen differs greatly in the longer and shorter stamens of the two 

 other forms, I carefully compared that of the two sets of stamens 

 in this form : in both the pollen-grains are yellow, but they are a 

 little larger in the longer than in the shorter stamens. The dif- 

 ference is slight, so that I convinced myself of its reality only by 

 putting two small heaps close together under the compovmd mi- 

 * Hist. Phys. des Plantes d'Europe, torn, ii., 1841, p. 371. Wii-tgen, " Ueber 

 Lythrum salicaria und dessen.Formen," Vcrfiand. des naturhist. Vereins der 

 prcuss. Rhcinl,, 5. Jahrgaug, 1848, S. 7. 



