I find that when irregularly shaped stones are embedded in the roots of trees, small parcels of earth are very frequently enclosed 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 enclosed by the roots of an oak about fifty years old, three dicotyledonous plants germinated: I am certain 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 killed 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 thirty 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 may safely assume that under such circumstances their rate of flight would often be thirty-five miles an hour; and some authors have given a far higher estimate.

I have never seen an instance of nutritious seeds passing through the intestines of a bird; but hard seeds of fruit pass uninjured through even the digestive organs of a turkey.