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 
