94 HKTEEOSTYLED DIMOEPHIC PLANTS. Chap. III. 



one sex to the other, or from hermaphrodite to herma- 

 phrodite, we can recognise structure as manifestly ad- 

 apted to its action as to that of insects when these are 

 the carriers. We see adaptation to the wind in the in- 

 coherence of the pollen, — in the inordinate quantity- 

 produced (as in the Conifera3, Spinage, &c.), — in the 

 dangling anthers well fitted to shake out the pollen, — 

 in the absence or small size of the perianth, — in the 

 protrusion of the stigmas at the period of fertilisation, 

 — in the flowers being produced before they are hidden 

 by the leayes, — and in the stigmas being downy or 

 plumose (as in the Graminese, Docks, &c.), so as to 

 secure the chance-blown grains. In plants which are 

 fertilised by the wind, the flowers do not secrete nectar, 

 their pollen is too incoherent to be easily collected by 

 insects, they have not bright-coloured corollas to serve 

 as guides, and they are not, as far as I have seen, 

 visited by insects. When insects are the agents of fer- 

 tilisation (and this is incomparably the more frequent 

 case with hermaphrodite plants), the wind plays no 

 part, but we see an endless number of adaptations to 

 ensure the safe transport of the pollen by the living 

 workers. These adaptations are most easily recognised 

 in irregular flowers ; but they are present in regular 

 flowers, of which those of Linum ofi"er a good instance, 

 as I will now endeavour to show. 



I have already alluded to the rotation of each sepa- 

 rate stigma in the long-styled form of Linwm perenne. 

 In both forms of the other heterostyled species and in 

 the homostyled species of Linum which I have seen, 

 the stigmatic surfaces face the centre of the flower, 

 with the furrowed backs of the stigmas, to which the 

 styles are attached, facing outwards. This is the case 

 with the stigmas of the long-styled flowers of L. 

 perenne whilst in bud. But by the time the flowers 



