THE PATAGONIAN RHEA, 455 



and swims with equal facility. Tlio pctiso was seen by "NYallis at Batclielor's river, in 

 the Strait of llagellaii. Dobri>;hoffer, in his account of the Abiponos (1749), also notices 

 it, and distinguishes between it and the common rhea. " Tliosc," ho says, meaning- 

 the latter, " which inhabit the plains of Buenos Ayres and Turcuman, are larger, and 

 have black, white, and gray feathers ; those, the petises, near the fcstrait of Magellan, arc 

 smaller and more beautiful ; for their white feathers are tipped with black at the 

 extremitv, and their black ones, in like manner, terminate in white." M. D'Orbigny 

 heard of the petlse, and endeavoured, though without success, to procure specimens wliile 

 at Rio Negro. To Jlr. Darwin Is due the merit of its hitroductlon to science, and all 

 definite details concerning it. 



