364 Dr. Emil A. Goeldi on the 



verified it myself, and in my collection of birds of the Serra- 

 des-Org;Tos Mountains, Rio de Janeiro, are specimens of the 

 eggs of Cassidix taken with my own hands out of nests of 

 the Ostinops. I have seen the eggs of both together in one 

 nest, and have several times reared young ones of the 

 Cassidix along with their yellow-tailed brethren. The little 

 Molothrus has, besides some others, the popular name 

 "Parasita^''; Cassidix oryzivora is called "Melro^^ in Rio 

 de Janeiro, in Northern Brazil ''Grautia^' (an abbreviation 

 of the Tupi words "guira-vina" = black-bird)"^. 



When I arrived in Para, I was surprised at being told by 

 several persons that the "Grauna^^ has the habit of laying 

 its eggs in the nest of the '' Japiim^' ( = Cassicus per'sicus). 

 I had thus an interesting confirmation of my own observations 

 in Rio de Janeiro, and have come to the conclusion that 

 Cassidix oryzivora is parasitic everywhere, choosing in North 

 and South Brazil for its eggs the nests of the respective Cassi- 

 cine species, the size of which agrees best with its own. There 

 is thus in Cassidix orgzivora a remarkable example of the 

 adaptation of a bird with cuckoo-habits to different local 

 faunistic relations, and a nice parallel to the phenomenon 

 offered by Cassicus persicus, which changes its nesting- 

 material in accordance with the change of plants in different 

 latitudes f. 



I may add that Cassicus persicus had eggs when we were 

 in Connany, between October lltli and 26tli, 1895, and that 



* As regards popular names much care is always necessary. The 

 same name—" Graiiua," for example — is used in Southern Brazil for 

 Ajjhobus chopi and on the island of Marojo for Atuhlycercus scditarius. — 

 E. A. G. 



t Just as the material used by Cassicus persicus for its nest in Bahia 

 (and southwards) is different from that used by the same bird in Para, 

 the material employed by Ostinops decumanus in these two countries 

 respectively is also different. I have stated, that in Southern Brazil 

 Ostinops uses exclusively the " Barla de \elho" (Tilkmdsia usneoides), 

 and that these southern nests are of a greyish colour. On the Amazon 

 the material employed by this bird is composed of — (1) a black hairy 

 substance, very like horsehair or delicate and elongated roots [which 

 botanical researches in the Para Museum prove to be a most interesting 

 lichen, but of which it is not v'et possible to ascertain the exact 



