64 MID-APRIL 
third smaller than either of the former birds, 
and usually few are to be seen, because they 
are much scarcer and keep themselves con- 
cealed, especially at nesting time. The wing 
feathers are brown and black, and the feathers 
of the tail are barred at the end with black 
and show white when the tail is expanded in 
flight. It, too, has iridescent feathers on 
the neck. Its note is a distinct ‘ tury, tur’: 
hence its name. It is migratory, and 
never remains with us in winter. It 1s 
often kept in confinement. Tame pigeons, 
in their endless varieties, have been bred 
through many generations from the Rock 
Dove, a small blue pigeon found near the 
sea, where it inhabits caves and holes. The 
love that domestic pigeons have for a 
lump of rock salt to peck at is traceable 
to this fact. As has been before noticed, the 
eggs of birds that lay in dark holes and nests 
are in most cases white. But the familiar 
wild pigeons’ nests are never in the dark, so we 
must conclude, I suppose, that their remote 
ancestors were of the sea type, and that in 
