GENERAL DISTRIBUTION. 
177 
Owing to the extraordinary capabilities of distribution 
possessed by birds, and the continuous discovery of 
new species, the number of these indigenous to each 
quarter of the globe has, as yet, not been determined. 
This can also be said even of Europe, in spite of the 
researches which have been made in all directions, birds 
occurring only in solitary instances in certain localities 
having been by common consent excluded from the list of 
that particular Fauna; for this reason : the catalogue of 
birds, found in any country favourably situated for 
feathered life, might easily be raised to double that of the 
really indigenous species. According to Swainson, the 
birds of Europe number 338 species ; according to Blasius, 
490 ; Degland gives 507 ; Bonaparte, 530 ; Schinz, 550 ; 
and my father’s list greatly exceeds this. Of the 530 
species mentioned by Bonaparte, there are 53 species of 
Raptores ; 241 Passeres; 5 Pigeons ; 18 species of Galli¬ 
naceous birds ; 93 species of Waders ; and 120 Swimming- 
birds. Every fresh visitant is added to those already 
named; and thus the list of species grows larger almost 
every year. This easily explains why the list of birds 
to be found in a country is so disproportionate to the 
number of its mammals. The latter are, so to speak, 
chained to their home; while the former can leave it 
whenever they please. 
Despite, however, its wonderful adaptation for travel, 
the bird seems coerced by some hidden and unconquer¬ 
able impulse, an endless yearning, to return to its early 
home. This creature, to whom the earth is one universal 
paradise; roaming from zone to zone; spanning the 
vast ocean at a flight; able to soar higher and higher, 
until its native earth vanishes from its sight, veiled by 
the blue mist beneath; a being which can, at will, 
