The result was that 18/98 of his seeds of different kinds floated for forty-two days, and were then capable of germination.

But I do not doubt that plants exposed to the waves would float for a less time than those protected from violent movement as in our experiments.

Therefore, it would perhaps be safer to assume that the seeds of about 10/100 plants of a flora, after having been dried, 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.