248 The Naturalist in La Plata. 



on the ground, resemble mice rather than birds ; 

 indeed, the Quichua name for one of these Synal- 

 laxes is ukalchtuka, 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, Oxyurus, 

 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; 1 ' 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. 



To birds placed at so great a disadvantage, by a 

 feeble flight and other adverse circumstances, in the 

 race of life bright colours would certainly prove 

 fatal. It is true that brown is not in itself a pro- 

 tective colour, and the clear, almost silky browns 

 and bright chestnut tints in several species are 

 certainly not protective ; but these species are suf- 

 ficiently protected in other ways, and can afford to 

 be without a strictly adaptive colour, so long as they 

 are not conspicuous. In a majority of cases, how- 

 ever, the colour is undoubtedly protective, the 



