How great their adaptiveness and variability must be when we find that every portion of the South American continent is occupied by them; for there is really no climate, and no kind of soil or vegetation, which does not possess its appropriate species, modified in colour, form, and habits to suit the surrounding conditions. In the tropical region, so rich in bird life of all kinds, in forest, marsh, and savanna, they are everywhere abundant--food is plentiful there; but when we go to higher elevations avd cold sterile deserts, where their companion families of the tropics dwindle away and disappear, the creepers are still present, for they are evidently able to exist where other kinds would starve. On the stony plateaus of the Andes, and on the most barren spots in Patagonia, where no other bird is seen, there are small species of Synallaxis, which, in their obscure colour and motions on the ground, resemble mice rather than birds; indeed, the Quichua name for one of these Synallaxes is _ukatchtuka,_ or mouse-bird. How different is the life habit here from what we see in the tropical groups--the large birds with immense beaks, that run vertically on the trunks of the great forest trees! At the extreme southern extremity of the South American continent we find several species of Cin-clodes, seeking a subsistence like sandpipers on the beach; they also fly out to sea, and run about on the floating kelp, exploring the fronds for the small marine animals on which they live. In the dreary forests of Tierra del Fuego another creeper, Uxyurus, is by far the commonest bird. "Whether high up or low down, in the most gloomy, wet, and scarcely penetrable ravines," says Darwin, "this little bird is to be met with;" and Dr. Cunningham also relates that in these wintry, savage woods he was always attended in his walks by parties of these little creepers, which assembled to follow him out of curiosity.