12 



PATAGONIAN EXPEDITIONS I ZOOLOGY. 



from island to island in the sea, where the distance . is not great. The 

 remarkable partial webbing of the feet in the downy young here noticed 

 must be of great advantage to these weaker birds in fol- 

 lowing the parent bird during such passages. 



FIG. 9. 



Several adults, immature, and nestlings have been received 

 by the British Museum from the Valle del Lago Blanco, 

 Chubut, January 10, 1900 ; collected by J. Koslowsky. 

 Rhea darwini. The Princeton Expeditions obtained many adults of 

 Foot of downy Rj iea darwini, Gould, and most of these were lost as pre- 

 sh wiT th v i ous ly described (page 4 this volume). However, two 

 pads. Natural a dult and a brood of seven downy young form a series of 

 great value and are herewith cited in detail : 



size. 



Darwin's account of this Rhea is here appended: 



"When at the Rio Negro in northern Patagonia, I repeatedly heard 

 the Guachos talking of a very rare bird which they called Avestruz Petise. 

 They described it as being less than the common ostrich (which is there 

 very abundant), but with a very close general resemblance. They said 

 its colour was dark and mottled, and that its legs were shorter, and 

 feathered lower down than those of the common ostrich. It is more easily 

 caught by the bolas than the other species. The few inhabitants who had 

 seen both kinds, affirmed they could distinguish them apart from a long 

 distance. The eggs of the small species appeared, however, 'more gener- 

 ally known ; and it was remarked, with surprise, that they were very little 

 less than those of the Rhea, but of a slightly different form, and with a 

 pale tinge of pale blue. This species occurs most rarely on the plains 



