COMMON RHEA 231 



before the appearance of the European mounted 

 hunter, enables it to see far ; its dim grey plumage, 

 the colour of the haze, made it almost invisible to 

 the eye at a distance, the long neck being so slender 

 and the bulky body so nearly on a level with the tall 

 grasses ; while its speed exceeded that of all other 

 animals inhabiting the same country. When watching 

 the chase of Ostriches in the desert pampas, abound- 

 ing in giant grasses, it struck me forcibly that this 

 manner of hunting the bird on horseback had brought 

 to light a weakness in the Rhea — a point in which 

 the correspondence between the animal and its en- 

 vironment is not perfect. The Rhea runs smoothly 

 on the siirface, and where the tall grass-tussocks are 

 bound together, as is often the case, with slender 

 twining plants, its legs occasionally get entangled, 

 and the bird falls prostrate, and before it can struggle 

 up again the hunter is close at hand and able to 

 throw the bolas — the thong and balls, which, striking 

 the bird with great force, wind about its neck, wings, 

 and legs, and prevent its escape. When I questioned 

 Ostrich hunters as to this point they said that it was 

 true that the Rhea often falls when running hotly 

 ptursued through long grass, and that the deer 

 (Cervtts campestris) never falls because it leaps over 

 the large tussocks and all such obstructions. This 

 small infirmity of the Rhea would not, however, 

 have told very much against it if some moderation 

 had been observed in huntix;^ it, or if the Argentine 

 Government had thought fit to protect it ; but in 

 La Plata, as in North America and South Africa, the 



