But the following fact is more important: the crops of birds do not secrete gastric juice, and do
not not 1859 1860 1861 1866 | not, 1869 1872 |
in the least injure, as I know by trial, in the least injure, as I know by trial, 1859 1860 1861 1866 |
as I know by trial, injure in the least 1869 1872 |
the germination of seeds;
now now 1859 1860 1861 | now, 1866 1869 1872 |
after a bird has found and devoured a large supply of food, it is positively asserted that all the grains do not pass into the gizzard for
12 12 1859 1860 | twelve 1861 1866 1869 1872 |
or even
18 18 1859 1860 | eighteen 1861 1866 1869 1872 |
hours. A bird in this interval might easily be blown to the distance of 500 miles, and hawks are known to look out for tired birds, and the contents of their torn crops might thus readily get scattered. Mr. Brent informs me that a friend of his had to give up flying carrier-pigeons from France to England, as the hawks on the English coast destroyed so many on their arrival. Some hawks and owls bolt their prey whole,
and and 1859 1860 1861 | and, 1866 1869 1872 |
after an interval of from twelve to twenty hours, disgorge pellets, which, as I know from experiments made in the Zoological Gardens, include seeds capable of germination. Some seeds of the oat, wheat, millet, canary, hemp, clover, and beet germinated after having been from twelve to twenty-one hours in the stomachs of different birds of prey; and two seeds of beet grew after having been thus retained for two days and
fourteen fourteen 1859 1860 1866 1869 1872 | four-teen 1861 |
hours.
Freshwater Freshwater 1859 1860 | Fresh-water 1861 1866 1869 1872 |
fish, I find, eat seeds of many land and water plants: fish are frequently devoured by birds, and thus the seeds might be transported from place to place. I forced many kinds of seeds into the stomachs of dead fish, and then gave their bodies to fishing-eagles, storks, and pelicans; these
birds birds 1859 1860 1861 | birds, 1866 1869 1872 |
after an interval of many hours, either rejected the seeds in pellets or passed them in their
excrement; excrement; 1859 1860 1861 1866 1872 | excre- ment; 1869 |
and several of these seeds retained
their their 1859 1860 1861 1866 | the 1869 1872 |
power of germination. Certain seeds, however, were always killed by this process. ↑8 blocks not present in 1859 1860 1861 1866; present in 1869 1872 | Locusts are sometimes blown to great distances from the land; I myself caught one 370 miles from the coast of Africa, and have heard of others caught at greater distances.
The Rev. R. T. Lowe informs
Sir C. Lyell that in November 1844 swarms of locusts visited the island of Madeira.
They were in countless numbers, as thick as the flakes of snow in the heaviest snowstorm, and extended upwards as far as could be seen with a telescope.
During two or three days they slowly careered round in the air
in an immense ellipse, at least five or six miles in diameter, and at night alighted on the taller trees
which were completely coated with them.
They then disappeared over the sea, as suddenly as they had appeared, and have not since visited the island.
Now, in parts of Natal it is believed by some of the
farmers, though on quite
insufficient evidence, that injurious seeds are introduced into their grass-land in the dung left by the great flights of locusts which often visit that country.
In consequence of this belief Mr. Weale sent me in a letter a small packet of the dried pellets, out of which I extracted under the microscope several seeds, and raised from them seven grass plants, belonging to two species, in
two genera.
Hence a swarm of locusts, such as that which visited Madeira, might readily be the means of introducing several kinds of plants into an island lying far from the mainland.
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