102 BIRDS OF LA PLATA 



When I was satisfied from their movements that 

 they had finished laying, I got up to the nest, and 

 was astonished to find ten eggs instead of five as I 

 had confidently expected ; for though the Common 

 Cow-birds had paid a great deal of attention to the 

 nest, I knew the Bay-wings would not allow them to 

 lay in it. 



The ten eggs in the nest were all unmistakably 

 Bay-wings' eggs ; and having observed before that 

 several females do occasionally lay together, I con- 

 cluded that in this case two females had laid in the 

 nest, though I had only seen two birds male and 

 female. After taking the ten eggs the Bay-wings 

 still remained, and in a very short time they appeared 

 to be laying again. When I had reason to think that 

 the full complement was laid, I visited the nest and 

 found five eggs in it; these I also took, and con- 

 cluded that the second female had probably gone 

 away, after having been deprived of her first clutch. 

 During all this time the Screaming Cow-birds 

 remained in the neighbourhood and occasionally 

 visited the tree ; but to my very great surprise the 

 Bay-wings still stubbornly remained, and by-and-by 

 I found that they were going to lay again the fourth 

 time ! When I next visited the nest there were two 

 eggs in it ; I left them and returned three days 

 later, expecting to find five eggs, but found seven ! 

 certainly more than one female had laid in the nest on 

 this occasion. After I had taken these last seven eggs 

 the Bay-wings left; and though the Screaming 

 Cow-birds continued to make occasional visits to 



