Chap. Xt. 
MEANS OF DISPERSAL. 
361 
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 
on examination, 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 in the longest transport: out of 
one small portion of earth thus completely enclosed by 
wood in an oak about 50 years old, three dicotyle¬ 
donous plants germinated: I am certain of the accuracy 
of this observation. Again, I can show that the car¬ 
casses of birds, when floating on the sea, sometimes 
escape being immediately devoured; and seeds of 
many kinds 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 salt-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 may I think safely assume that under such circum¬ 
stances their rate of flight would often be 35 miles an 
hour; and some authors have given a far higher esti¬ 
mate. 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. In the course of two 
months, I picked up in my garden 12 kinds of seeds, 
out of the excrement of small birds, and these seemed 
perfect, and some of them, which I tried, germinated. 
