366 
DARWINISM 
CHAP. 
per century were carried to an oceanic island, that island 
might become rapidly overrun by the plant, if the conditions 
were favourable to its growth and reproduction. It is further 
objected that search has been made for such seeds, and they 
have not been found. Professor Kernel' of Innsbruck examined 
the snow on the surface of glaciers, and assiduously collected 
all the seeds he could find, and these were all of plants which 
grew in the adjacent mountains or in the same district. In 
like manner, the plants growing on moraines were found to 
be those of the adjacent mountains, plateaux, or lowlands. 
Hence he concluded that the prevalent opinion that seeds 
may be carried through the air for very great distances “ is 
not supported by fact.” 1 The opinion is certainly not 
supported by Kerner’s facts, but neither is it opposed by 
them. It is obvious that the seeds that would be carried by 
the wind to moraines or to the surface of glaciers would be, first 
and in the greatest abundance, those of the immediately 
surrounding district ; then, very much more rarely, those 
from more remote mountains; and lastly, in extreme rarity, 
those from distant countries or altogether distinct mountain 
ranges. Let us suppose the first to be so abundant that a 
single seed could be found by industrious search on each 
square yard of the surface of the glacier; the second so scarce 
that only one could possibly be found in a hundred yards 
square ; while to find one of the third class it would be 
necessary exhaustively to examine a square mile of surface. 
Should we expect that one ever to be found, and should the fact 
that it could not be found be taken as a proof that it was not 
there ? Besides, a glacier is altogether in a bad position to 
receive such remote wanderers, since it is generally surrounded 
by lofty mountains, often range behind range, which would 
intercept the few air-borne seeds that might have been carried 
from a distant land. The conditions in an oceanic island, on the 
other hand, are the most favourable, since the land, especially 
if high, will intercept objects carried by the wind, and will 
thus cause more of the solid matter to fall on it than on an 
equal area of ocean. We know that winds at sea often blow 
violently for days together, and the rate of motion is indicated 
by the fact that 72 miles an hour was the average velocity 
1 See Nature, vol. vi. p. 164, for a summary of Keruer’s paper. 
