ON THE WINGS OF THE WIND. 39; 



open country, that the plant is known to farmers in America as 

 fireweed, because it always springs up at once over whole square 

 miles of charred and smoking soil after every devastating forest 

 fire. It travels fast, for it travels like Ariel. In much the same 

 way, the colt'sf oot grows on all new English railway banks, be- 

 cause its winged seeds are wafted everywhere in myriads on the 

 winds of March. All the willows and poplars have also winged 

 seeds ; so have the whole vast tribe of hawkweeds, groundsels, 

 ragworts, thistles, fleabanes, cat's-ears, dandelions, and lettuces. 

 Indeed, one may say roughly, there are very few plants of any 

 size or importance in the economy of nature which don't deliber- 

 ately provide, in one way or another, for the dispersal and dis- 

 semination of their fruits or seedlings. 



Why is this ? Why isn't the plant content just to let its grains 

 or berries drop quietly on to the soil beneath, and there shift for 

 themselves as best they may on their own resources ? 



The answer is a more profound one than you would at first 

 imagine. Plants discovered the grand principle of the rotation 

 of crops long before man did. The farmer now knows that if he 

 sows wheat or turnips too many years running on the same plot, 

 he " exhausts the soil," as we say deprives it of certain special 

 mineral or animal constituents needful for that particular crop, 

 and makes the growth of the plant, therefore, feeble or even im- 

 possible. To avoid this misfortune, he lets the land lie fallow, or 

 varies his crops from year to year according to a regular and de- 

 liberate cycle. Well, natural selection forced the same discovery 

 upon the plants themselves long before the farmer had dreamed 

 of its existence. For plants, being, in the strictest sense, " rooted 

 to the spot," absolutely require that all their needs should be sup- 

 plied quite locally. Hence, from the very beginning, those plants 

 which scattered their seeds widest throve the best ; while those 

 which merely dropped them on the ground under their own shad- 

 ow, and on soil exhausted by their own previous demands upon 

 it, fared ill in the struggle for life against their more discursive 

 competitors. The result has been that in the long run few species 

 have survived, except those which in one way or another arranged 

 beforehand for the dispersal of their seeds and fruits over fresh 

 and unoccupied areas of plain or hillside. 



I don't, of course, by any means intend to assert that seeds al- 

 ways do it by the simple device of wings or feathery projections. 

 Every variety of plan or dodge or expedient has been adopted in 

 turn to secure the self -same end ; and, provided only it succeeds in 

 securing it, any variety of them all is equally satisfactory. One 

 might parallel it with the case of hatching birds' eggs. Most 

 birds sit upon their eggs themselves, and supply the necessary 

 warmth from their own bodies. But any alternative plan that 



