280 ON THE DESCENT OF BIKDS. 



nearly full-grown. As I was very anxious to make out for certain the 

 species, 1 bought it, and, after a good deal of trouble, succeeded in 

 getting it alive to Recife, and eventually to London, where, however, 

 unfortunately, it did not live long. The " Ema," as the Ehea is called 

 by the Brazilians, is well known to the people in the Sertoes ; it is now 

 said to be rare near Aguas Bellas, but, I was told, is still found pretty 

 numerously (as is the Cariama) in the open grass-covered country near 

 San Bento. Indeed during the secca, or drought, that has prevailed for 

 the last few summers in this part of the country, and which resulted in 

 a general famine, the " Emas " became so tame through hunger that they 

 might be found close to the town itself, and even came into the gardens, 

 and so were caught. My friend Mr. "Weaver, of Quipapa, told me he 

 had had a young live Ema for some time in his house, which had been 

 sent him as a present by a lady. This specimen came from Pianco, a 

 small town in the province of Parahyba ; so that evidently the range of 

 Rhea macrorhyncha extends to the north of Pernambuco. I hope, ere 

 long, to obtain, through the agency of some of my Brazilian friends, 

 specimens of the eggs and young of this bird to compare with those of 

 the commoner species. What the exact northern extension of the latter 

 is I do not exactly know, though it certainly extends north of the Biver 

 Plate into Uruguay ; probably the barrier between the two species is a 

 continuously wooded country lying between that district and the Sertoes 

 of Bahia, where the species is also most probably found. Capt. Burton, 

 who alludes to the existence of a Ehea in Brazil several times, saw one 

 himself on the banks of the S. Francisco near the Bio do Corrente, above 

 Bom Jardim (' Highlands of Brazil/ ii. p. 296), and others at Jaguara 

 (I. c. ii. p. 26), in the province of Minas. 



I hope on some future occasion to be able to compare the skeletons of 



Ibis, 1881, Rhea americana and R. macrorhynclia ; externally, though certainly 



p< * closely allied, the latter species is distinguishable by its generally 



browner colouring, by the darker crown, which is nearly black, and by its 



longer bill. 



43 - THE DESCENT OP BIRDS* 



THERE is one passage in the report of Prof. Mivart's lecture on 

 chamseleons (' Nature/ vol. xxiv. p. 338) that I cannot allow to pass 

 without demurring to, and that is the suggested probability of a " double 



* 'Nature/ xxiv. p. 380 (Aug. 25, 1881). 



