BIRD;:?, 149 



cies inhabiting these islands is peculiar, but allied 

 to one from the southern parts of South America, 

 The far gi-eater peculiarity of the land-birds, name- 

 ly, twenty-five out of twenty-six being new species, 

 or at least new races, compared with the waders 

 and web-footed birds, is in accordance with the 

 greater range which these latter orders have in all 

 parts of the world. We shall hereafter see this 

 law of aquatic forms, whether marine or fresh- 

 water, being less peculiar at any given point of the 

 earth's surface than the ten-estrial forms of the 

 same classes, strikingly illustrated in the shells, 

 and in a lesser degree in the insects of this archi- 

 pelago. 



Two of the waders are rather smaller than the 

 same species brought fi'om other places : the swal- 

 low is also smaller, though it is doubtful whether 

 or not it is distinct from its analogue. The two 

 owls, the two tyrant flycatchers (Pyrocephalus), and 

 the dove, are also smaller than the analogous but 

 distinct species to which they are most nearly re- 

 lated ; on the other hand, the gull is rather larger. 

 The two owls, the swallow, all three species of 

 mocking-thrush, the dove in its separate colours, 

 though not in its whole plumage, the Totanus, and 

 the gull, are likewise duskier coloured than their 

 analogous species ; and in the case of the mock- 

 ing-thrush and Totanus, than any other species of 

 the two genera. With the exception of a wren with 

 a fine yellow breast, and of a tyrant flycatcher wdth 

 a scarlet tuft and breast, none of the birds are 

 brilliantly coloured, as might have been expected 

 in an equatorial dist]-ict. Hence it would appear 

 probable that the same causes which here make 

 the immigrants of some species smaller, make most 

 of the peculiar Galapageian species also smaller, as 

 well as very generally more dusky coloured. All 

 N 2 



