94 HETBROSTYLBD DIMORPHIC PLANTS. Chap. IIL 



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

 phrodite, we can recognise structure as manifestly 

 adapted to its action as to that of insects when these 

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

 incoherence of the pollen, — in the inordinate quantity 

 produced (as in the Coniferaj, 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 leaves,- — and in the stigmas being downy or 

 plumose (as in the Graminea3, 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 fertilisa- 

 tion (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 irregu- 

 lar flowers; but they are present in regular flowers, 

 of which those of Linum offer 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 Linum 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 



