234 
BIRD-LIFE. 
case is it so evident as amongst those birds which 
essentially live on the ground. They seem to form part 
and parcel of the soil on which they live; as the one 
changes so does the other; that is to say, there are certain 
birds which are to be found only where the colour of 
their plumage corresponds with that of the soil. The 
Skylark looks like one of the clods on our fields. The Lark 
of Tartary resembles a lump of the soil of the steppes of 
South-eastern Europe or Central Asia; in the desert I 
not only met with an isabel-coloured Sand-lark, but also 
with yellow Crested Larks. In parts of the arid plains of 
Kordovan, where the soil was of a ferruginous colour, 
I discovered an ochre-coloured Bunting-lark. The same 
holds good with the Gallinacece, though to a still greater 
extent. I have already mentioned that with some species 
of this family the female, which mostly lives on the 
ground, alone adopts the colour of the earth, while the 
plumage of the male is highly coloured; I have also 
stated the reasons for this arrangement. Besides these, 
I have mentioned other members of the family which 
bear the impress of the localities they inhabit, and have 
especially referred to one particular group—the Ptarmi¬ 
gans—to which we will yet further turn our attention. 
This bird inhabits the high mountains of all the 
alpine districts, as well as the arctic regions, and is 
especially remarkable, above all other members of the 
group, for the peculiar way in which it changes its 
plumage. Its home can boast, so to speak, of only two 
seasons—winter and summer; and the adaptation of the 
plumage of this bird to each season in turn is in per¬ 
fect harmony with the same. In the shape of its body 
it, on the whole, resembles other groups among the 
Gallinacece; its plumage, however, distinguishes it from 
