British North American Plants. 465 



lead them into situations where seeds may adhere to their 

 feathers or in mud to their legs and feet, and that great 

 numbers of seeds are for the purpose of diffusion supplied by 

 nature with means of adhesion to objects, whether birds or 

 quadrupeds, with which they are brought into contact —are 

 all of them circumstances, in progress for long centuries 

 past, the one fitting into the other, which have been instru- 

 mental in the gradual and wide dispersion of many plants. 

 The popular view of the economic purposes of fruits is that 

 they are provided by nature as food for man and the lower 

 animals. Perhaps an even more immediate purpose in 

 their colour and flavour, is that they may attract birds and 

 quadrupeds — as the colours of flowers do insects — and that 

 the seeds, by being carried great distances in the crops and 

 stomachs of these creatures, should thus have an important 

 means of diffusion. 



Wind is, however, the most important factor in distribu- 

 tion. Many plants have their seeds furnished with appen- 

 dages to be utilized in connection with the wind, and such 

 plants have a generally wider distribution than those not so 

 furnished. The different species of maple, ash and pine, 

 have what might be termed wings attached to their seeds, 

 and these are undoubtedly thus provided that in falling at 

 maturity, the seeds may be carried by the wind beyond the 

 parent tree. The seeds of most of the Composite are sup- 

 plied with plumes or awns which form an important means 

 by which they are distributed, and thus this, in America, 

 most extensive of the phsenogamous orders is, though geo- 

 logically recent, of wide diffusion. "Whilst, however, the 

 ordinary winds have their local effects in scattering seeds, 

 it is to hurricanes and tornadoes, and even ordinary high 

 winds, that we must look for the carrying of them to great 

 distances. It is not difficult to suppose that most seeds can 

 be so carried. Where the fruit is heavy, as in the case of 

 the oaks, hickories, walnut, butternut, chestnut, plum and 

 cherries, the range of the species is relatively circumscribed. 

 The seeds of herbaceous plants generally are, however, light, 

 almost feathery, in weight — a circumstance which like the 

 awns and wings provided as appendages to many of them, 



