l62 THE DISPERSAL OF SHELLS. 



as Mr. Darwin's remarks suggest, may possibly be 

 transported, especially during gales, under exceptionally 

 favourable circumstances, to new homes perhaps several 

 hundreds of miles from their original habitats. At 

 ordinary times birds often fly a long way to feed — wood 

 pigeons, for instance, do so when necessary — and if 

 struck down by birds of prey when returning home, the 

 living contents of their crops might possibly be liberated 

 at considerable distances from the feeding-ground. 

 There is no actual proof, as far as I know, that shells 

 have ever been scattered from crops in the manner here 

 indicated, but an observation of much interest in this 

 connection has been made by Mr. Aplin, who tells me 

 that he once noticed a little heap of barley, evidently 

 carried from a distance^ lying among the remains of two 

 wood pigeons which had been killed by a hawk, pro- 

 bably a peregrine. Even when a snail-eating bird hap- 

 pens to be killed on its feeding-ground, the bird of prey, 

 " soaring across hill and dale " to a hiding-place, and 

 carrying its victim with it, might ultimately scatter a 

 few snails miles from their original home; it maybe 

 remarked, however, as Mr. Aplin points out, that except 

 in the breeding season when they have young, hawks, 

 etc., often or usually eat their kills on the spot, or close 

 to it j but it is undoubtedly probable, as Mr. Cordeaux 

 assures me, that both seeds and shells have been dis- 

 tributed, to some extent, by hawks, owls, etc. sometimes 

 devouring their victims at a distance from where they 

 were struck down. It seems possible, also, that snails 

 in the crops of dead birds may be floated, at rare 



