ore mentioned
that earth occasionally adheres in some quantity to the feet and beaks
of birds. Wading birds, which frequent the muddy edges of ponds, if
suddenly flushed, would be the most likely to have muddy feet. Birds
of this order wander more than those of any other; and are occasionally
found on the most remote and barren islands of the open ocean; they
would not be likely to alight on the surface of the sea, so that any
dirt on their feet would not be washed off; and when gaining the land,
they would be sure to fly to their natural fresh-water haunts. I do not
believe that botanists are aware how charged the mud of ponds is with
seeds: I have tried several little experiments, but will here give only
the most striking case: I took in February three tablespoonfuls of mud
from three different points, beneath water, on the edge of a little
pond; this mud when dry weighed only 6 and 3/4 ounces; I kept it covered
up in my study for six months, pulling up and counting each plant as it
grew; the plants were of many kinds, and were altogether 537 in number;
and yet the viscid mud was all contained in a breakfast cup! Considering
these facts, I think it would be an inexplicable circumstance if
water-birds did not transport the seeds of fresh-water plants to
unstocked ponds and streams, situated at very distant points. The same
agency may have come into play with the eggs of some of the smaller
fresh-water animals.

Other and unknown agencies probably have also played a part. I have
stated that fresh-water fish eat some kinds of seeds, though they reject
many other kinds after having swallowed them; even small fish swallow
seeds of moderate size, as of the yellow water-lily and Potamogeton.
Herons and other birds, century after century, have gone on daily
devouring fish; they then take flight and go to other waters, or are
blown across the sea; and we have seen that seeds retain their power of
germination, when rejected many hours afterwards in pellets or in
the excrement. When I saw the great size of the seeds of that fine
water-lily, the Nelumbium, and remembered Alph. de Candolle's remarks
on the distribution of this plant, I thought that the means of its
dispersal must remain inexplicable; but Audubon states that he found
the seeds of the great southern water-lily (probably according to Dr.
Hooker, the Nelumbium luteum) in a heron's stomach. Now this bird must
often have flown with its stomach thus well stocked to dista