386 MEANS OF DISPERSAL. 



seeds, out of tlie excrement of small birds, and these 

 seemed perfect, and some of them, which were tried, ger- 

 minated. But the following fact is more important: the 

 crops of birds do not secrete gastric juice, and do not, as I 

 know by trial, injure in the least the germination of seeds; 

 now, 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 twelve or even eighteen hours. A 

 bird in this interval might easily be blown to the distance 

 of five hundred miles, and hawks are known to look out 

 for tired birds, and the contents of their torn crops might 

 thus readily get scattered. Some hawks and owls bolt 

 their prey whole, and, after an interval of from twelve to 

 twenty hours, disgorge pellets, which, as I know from ex- 

 periments 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 hours. Fresh-water 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, after an interval of many 

 hours, either rejected the seeds in pellets or passed them in 

 their excrement; and several of these seeds retained the 

 power of germination. Certain seeds, however, were 

 always killed by this process. 



Locusts are sometimes blown to great distances from the 

 land. I m3^self caught one 370 miles from the coast of 

 Africa, and have heard of others caught at greater distances. 

 The Rev. R. T. Lowe informed Sir C. Lyell that in No- 

 vember, 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 

 upward as far as could be seen with a telescope. During 

 two or three days they slowly careered round and round in 

 an immense ellipse, at least five or six miles in diameter, 

 and at night alighted on the taller trees, which were com- 

 pletely coated with them. They then disappeared over the 



