GEOGRAPHICAL DISTRIBUTION 163 



could be floated across a space of sea 900 miles in 

 width, and would then germinate. The fact of the 

 larger fruits often floating longer than the small is 

 interesting; as plants with large seeds or fruit which, 

 as Alph. de Candolle has shown, generally have restricted 

 ranges, could hardly be transported by any other means. 



Seeds may be occasionally transported in another 

 manner. Drift timber is thrown up on most islands, 

 even on those in the midst of the widest oceans; and 

 the natives of the coral-islands in the Pacific procure 

 stones for their tools solely from the roots of drifted 

 trees, these stones being a valuable royal tax. I find 

 that when irregularly shaped stones are imbedded in the 

 roots of trees, small parcels of earth are frequently in- 

 closed in their interstices and behind them — so perfectly 

 that not a particle could be washed away during the 

 longest transport: out of one small portion of earth thus 

 completely inclosed by the roots of an oak about 50 years 

 old, three dicotyledonous plants germinated: I am cer- 

 tain of the accuracy of this observation. Again, I can 

 show that the carcasses of birds, when floating on the 

 sea, sometimes escape being immediately devoured: and 

 many kinds of seeds in the crops of floating birds long 

 retain their vitality: peas and vetches, for instance, are 

 idlled by even a few days' immersion in sea- water; but 

 some taken out of the crop of a pigeon which had floated 

 on artificial sea-water for 30 days, to my surprise nearly 

 all germinated. 



Living birds can hardly fail to be highly effective 

 agents in the transportation of seeds. I could give many 

 facts showing how frequently birds of many kinds are 

 blown by gales to vast distances across the ocean. We 



