THE SEED. 173 
Polar seas often meet with icebergs loaded with an enormous mass 
of débris, mixed with earth and seeds. Seeds vegetate on these 
débris, and if the iceberg runs aground on some distant coast, 
where it melts, the seeds are deposited ; they soon produce plants, 
which are then spread over the country by the other influences 
already hinted at. 
The dissemination of seeds is helped, it is said, by the distant 
migration of granivorous birds. Yet the influence of birds appear 
to us of very little importance in the matter we are now consider- 
ing. Most birds completely destroy seeds in the act of digestion, 
and it is only exceptionally that seeds can traverse their intestinal 
canal without being destroyed. : 
“Omniverous birds,” says De Candolle, “often search for 
berries containing little hard seeds, as Grapes, Figs, Raspberries, 
Strawberries, Asparagus, Mistletoe, &e. Their stomach is not so 
destructive as that of the gallinaceous birds, and it appears that 
small seeds can traverse their alimentary canal without alteration. 
When these birds are migratory, which is often the case in tem- 
perate and northern regions, they carry the seeds to a great 
distance, particularly when, in the autumn, they leave northern 
climates to seek the sunny south, for at this season ripe fruits 
abound in the country. Thrushes, many of which change their 
country either in Europe or in America, can thus transport some 
sorts. When they eat too large a quantity of stone fruit, they 
digest them badly, and spread the seed with the kernels. There 
is an observation of Linnwus which assures us that the lark 
scatters a great many seeds in the fields.” 
By the same process, namely, by the imperfect digestion of seeds 
which have served them for nourishment, certain quadrupeds, 
particularly the herbivorous, are able to transport seeds from one 
part of the country toanother. This happens in the case of the rein- 
deer, an animal living in herds in the plains of Siberia, which, at a 
certain period, migrate in large numbers. Such also is the part 
played by the herds of cattle driven often to great distances in 
our European climates, and in general in all civilised countries. 
The action of men in the dissemination of vegetable seeds is 
shown in a thousand ways. We will borrow from M. Alphonse 
de Candolle some interesting remarks on this subject. — 
