OVEN-BIRD 201 
globular form with only a narrow opening, the wall 
on one side is curved inwards, reaching from the 
floor to the dome, and at the inner extremity an 
aperture is left to admit the bird to the interior or 
second chamber, in which the eggs are laid. A man’s 
hand fits easily into the first or entrance chamber, 
but cannot be twisted about so as to reach the eggs 
in the interior cavity, the entrance being so small 
and high up. The interior is lined with dry, soft 
grass, and five white pear-shaped eggs are laid. The 
oven is a foot or more in diameter, and is sometimes 
very massive, weighing eight or nine pounds, and 
so strong that, unless loosened by the swaying of 
the branch, it often remains unharmed for two or 
three years. The birds incubate by turns, and when 
one returns from the feeding-ground it sings its loud 
notes, on which the sitting bird rushes forth to join 
in the joyous chorus, and then flies away, the other 
taking its place on the eggs. The young are exceed- 
ingly garrulous, and when only. half-fledged may be 
heard practising trills and duets in their secure oven, 
in shrill tremulous voices, which change to the usual 
hunger-cry of young birds when the parent enters 
with food. After leaving the nest, the old and young 
birds live for two or three months together, only 
one brood being raised in each year. A new oven is 
built every year, and I have more than once seen a 
second oven built on the top of the first, when this 
has been placed very advantageously, as on a pro- 
jection and against a wall. 
A very curious thing occurred at the estancia house 
