DUSKY, GRAY, AND SLATE-COLORED 349 
made outside the nest. Both sexes share in the fun of 
nest-building, busily carrying short hair, feathers, and 
wool, and staying inside long enough to settle a much 
larger house. They work industri- yen 
ously for five or six days, until it 
seems as though at least a peck of 
trash had been tucked into the old 
oak tree. Then, after a day or so of 
play, the mother settles down 
to fourteen days of brooding | 
in the dark nest hole. In a 4% 
case which I recorded she 
was fed by her mate at short 
intervals during all this long 
incubation, and many were , 
the worms I saw him carry to 
her. He never entered the 
nest without first calling from 
outside, when she would an- 
\ 
swer and often come up to 4 
the door to be fed. We knew 7 " i 
at once when the young had @ 4) 4 
come out of the shells, for 
his exaggerated anxiety and 733. PLAIN TirMouse. 
: f i ** Busily carrying short hair, feathers, 
comical airs of business told «xd woo.” 
his secret. A listening at the doorway further confirmed 
this three days later. He now scolded at any approach to 
the nest and tried to win our attention to himself, while 
the female slipped in and out with food. My theory that 
most young birds are fed by regurgitation aé first was 
