164 HETEROSTYLED TRIMORPHIC PLANTS. CHAP. IV. 



the pollen from a single anther is far more than suffi- 

 cient to fertilise fully a stigma; since, in this as with 

 so many other plants, more than twelve times as much 

 of each kind of pollen is produced as is necessary to 

 ensure the full fertilisation of each form. From the 

 dusted condition of the bodies of the bees which I 

 caught on the flowers, it is probable that pollen of 

 various kinds is often deposited on all three stigmas; 

 but from the facts already given with respect to the 

 two forms of Primula, there can hardly be a doubt 

 that pollen from the stamens of corresponding length 

 placed on a stigma would be prepotent over any other 

 kind of pollen and obliterate its effects, even if the 

 latter had been placed on the stigma some hours pre- 

 viously. 



Finally, it has now been shown that Lythrum sali- 

 caria presents the extraordinary case of the same 

 species bearing three females, different in structure and 

 function, and three or even five sets (if minor differ- 

 ences are considered) of males; each set consisting of 

 half-a-dozen, which likewise differ from one another in 

 structure and function. 



Lythrum Grcefferi. I have examined numerous dried 

 flowers of this species, each from a separate plant, sent me 

 from Kew. Like L. salicaria, it is trimorphic, and the 

 three forms apparently occur in about equal numbers. In 

 the long-styled form the pistil projects about one-third of 

 the length of the calyx beyond its mouth, and is therefore 

 relatively much shorter than in L. salicaria; the globose 

 and hirsute stigma is larger than that of the other two 

 forms; the six mid-length stamens, which are graduated 

 in length, have their anthers standing close above and close 

 beneath the mouth of the calyx; the six shortest stamens 

 rise rather above the middle of the calyx. In the mid- 

 styled form the stigma projects just above the mouth of 

 the calyx, and stands almost on a level with the mid-length 

 stamens of the long- and short-styled forms ; its own long- 



