THE WIND AS CARRIER. 125 



not serve to allure the unconscious breeze; such 

 delicate adjustments of part to part as we saw in 

 the case of bee and blossom will no longer be 

 serviceable. What will most be needed now is 

 quantities of pollen ; and that pollen must hang 

 out in such a way from the cup as to be easily 

 dislodged by passing breezes. Hence wind-fertil- 

 ised flowers differ from insect-fertilised in the 

 following particulars. They have never brilliant 

 corollas or calyxes. The stamens are usually 

 very numerous; they hang out freely on long 

 stalks or filaments ; and they quiver in the wind 

 with the slightest movement. On the other hand, 

 the stigmas are feathery and protrude far from 

 the flower, so as to catch every passing grain of 

 pollen. More frequently than among the insect- 

 fertilised section, the sexes are separated on dif- 

 ferent plants or isolated in distinct masses on 

 neighbouring branches. But numerous devices 

 occur to prevent self-fertilisation. 



You must not suppose, again, that the wind- 

 fertilised plants form a group by themselves, dis- 

 tinct in origin from the insect-fertilised, as the 

 three-petalled group is distinct from the five- 

 petalled. On the contrary, wind-fertilised kinds 

 are found abundantly in both great groups; it is 

 a matter of habit; so much so that sometimes a 

 type has taken first to insect-fertilisation and then 

 to wind-fertilisation, with comparatively slight 

 differences in its external appearance. Closely 

 related plants often differ immensely in their mar- 

 riage customs; each has varied in the way that 

 best suited itself, according as insects or breezes 

 happened to serve it most readily. In my own 

 opinion all wind-fertilised plants are the descend- 

 ants of insect-fertilised ancestors ; but I do not 



