98 
INTRODUCTION OF BIRDS. 
birds, which are of no real value as food, but which, as we 
have seen, render a most important service by battling, in our 
behalf, as well as in their own, against the countless legions of 
humming and of creeping things, with wdiich the prolific pow¬ 
ers of insect life would otherwise cover the earth. 
Introduction of Birds. 
Man has undesignedly introduced into new districts per¬ 
haps fewer species of birds than of quadrupeds ; but the distri¬ 
bution of birds is very much influenced by the character of his 
industry, and the transplantation of every object of agricul¬ 
tural production is, at a longer or shorter interval, followed by 
that of the birds which feed upon its seeds, or more frequently 
upon the insects it harbors. The vulture, the crow, and other 
winged scavengers, follow the march of armies as regularly as 
the wolf. Birds accompany ships on long voyages, for the 
sake of the offal which is thrown overboard, and, in such cases, 
it might often happen that they would breed and become nat¬ 
uralized in countries where they had been unknown before.* 
There is a familiar story of an English bird which built its nest 
in an unused block in the rigging of a ship, and made one or 
two short voyages with the vessel while hatching its eggs. 
Had the young become fledged while lying in a foreign har¬ 
bor, they would of course have claimed the rights of citizen¬ 
ship in the country where they first took to the wing.f 
* Gulls hover about ships in port, and often far out at sea, diligently 
watching for the waste of the caboose. While the four great fleets, 
English, French, Turkish, and Egyptian, were lying in the Bosphorus, in 
the summer and autumn of 1853, a young lady of my family called my 
attention to the fact that the gulls were far more numerous about the ships 
of one of the fleets than about the others. This was verified by repeated 
observation, and the difference was owing no doubt to the greater abun¬ 
dance of the refuse from the cookrooms of the naval squadron most 
frequented by the birds. Persons acquainted with the economy of the 
navies of the states in question, will be able to conjecture which fleet was 
most favored with these delicate attentions. 
t Birds do not often voluntarily take passage on board ships bound for 
