Chap. XI. 
MEANS OF DISPERSAL. 
363 
of dry argillaceous earth from one foot of a partridge, 
and in this earth there was a pebble quite as large as 
the seed of a vetch. Thus seeds might occasionally be 
transported to great distances; for many facts could be 
given showing that soil almost everywhere is charged 
with seeds. Eeflect for a moment on the millions of 
quails which annually cross the Mediterranean; and can 
we doubt that the earth adhering to their feet would 
sometimes include a few minute seeds? But I shall 
presently have to recur to this subject. 
As icebergs are known to be sometimes loaded with 
earth and stones, and have even carried brushwood, 
bones, and the nest of a land-bird, I can hardly doubt 
that they must occasionally have transported seeds from 
one part to another of the arctic and antarctic regions, 
as suggested by Lyell; and during the Glacial period 
from one part of the now temperate regions to another. 
In the Azores, from the large number of the species 
of plants common to Europe, in comparison with the 
plants of other oceanic islands nearer to the mainland, 
and (as remarked by Mr. H. C. Watson) from the some¬ 
what northern character of the flora in comparison with 
the latitude, I suspected that these islands had been 
partly stocked by ice-borne seeds, during the Glacial 
epoch. At my request Sir C. Lyell wrote to M. Hartung 
to inquire whether he had observed erratic boulders 
on these islands, and he answered that he had found 
large fragments of granite and other rocks, which do 
not occur in the archipelago. Hence we may safely 
infer that icebergs formerly landed their rocky burthens 
on the shores of these mid-ocean islands, and it is at 
least possible that they may have brought thither the 
seeds of northern plants. 
Considering that the several above means of trans¬ 
port, and that several other means, which without 
R 2 
