178 HETEEOSTYLED TEIMOEPHIC PLANTS. Chap. IV. 



many more seeds, and the illegitimately fertilised 

 flowers are not quite so sterile. 



Oxdis rosea. — Hildebrand possessed in a living state 

 only the long-styled form of this trimorphic Chilian 

 species.* The pollen-grains from the two sets of 

 anthers differ in diameter as 9 to 7-5, or as 100 to 83. 

 He has further shown that there is an analogous 

 difference between the grains from the two sets of 

 anthers of the same flower in five other species of Oxalis, 

 besides those already described. The present species 

 differs remarkably from the long-styled form of the 

 three species prcTiously experimented on, in a much 

 larger proportion of the flowers setting capsules when 

 fertilised with their own-form pollen. Hildebrand fer- 

 tilised 60 flowers with pollen from the mid-length 

 stamens (of either the same or another flower), and 

 they yielded no less than 55 capsules, or 92 per cent. 

 These capsules contained on an average 5 • 62 seeds ; 

 but we have no means of judging how near an approach 

 this average makes to that from flowers legitimately 

 fertilised. He also fertilised 45 flowers with pollen 

 from the shortest stamens, and these yielded only 17 

 capsules, or 31 per cent., containing on an average 

 only 2 • 65 seeds. We thus see that about thrice as 

 many flowers, when fertilised with pollen from the 

 mid-length stamens, produced capsules, and these 

 contained twice as many seeds, as did the flowers 

 fertilised with pollen from the shortest stamens. 

 It thus appears (and we find some evidence of 

 the same fact with 0. speciosa), that the same rule 

 holds good with Oxalis as with Lythrum salicaria ; 

 namely, that in any two unions, the greater the in- 

 equality in length between the pistils and stamens, or. 



' Monatsber. der Akad. der Wiaa. Berlin,' 1866, p. 372. 



