flying
rapidly back and forth bringing bits of moss from the brush to put in
their nest.

They worked independently, each hunting moss and placing it to its own
satisfaction. What one did the other would be well pleased with, I felt
sure. But while each worked according to its own ideas, they always
appeared to be working together; they could not bear to be out of sight
of each other long at a time. When the small father bird found himself
at the nest alone, after placing his material he would stand and call to
let his pretty mate know that he was waiting for her; or else sit down
by the nest and warble over such a contented, happy little lay it warmed
my heart just to listen to him.

When his mate appeared the merry birds would chase off for a race
through the treetops. Song and play were mingled with their work, but,
for all that, the happy builders' house grew under their hands, and they
kept faithfully at their task of preparing the home for their little
brood. Once the small, dainty mother bird,--surely it must have been
she,--after putting in her bit of moss, settled down in the nest and
sat there the picture of quiet happiness.

This was all I saw of the nest builders that year. A great storm swept
through the valley, and it must have washed away the frail mossy cup,
for it was gone and the tree was deserted. Nevertheless, the birds had
been so attractive, and their nest so interesting, that through the five
years that passed before my return to California I kept their memory
green, and could never think of them without tenderness--though I could
call them by no name. If they had only worn red feathers in their caps,
it would have been some clue to their coats-of-arms; but, out of hand,
there seemed to be nothing to mark the plain, little, greenish gray
birds from half a dozen of their cousins.

When I finally returned to the California ranch, one of my first
thoughts was for the moss nest makers up in the oaks. Now I had a chance
to solve the mystery without harming one of their pretty feathers, for
by long and patient watching I might get near enough to puzzle out the
'spurious primary' and the subtle distinctions of tint that make such a
difference in calling birds by their right names.

For six weeks I watched and listened in vain, but one day when riding up
the canyon rejoicing at the new life that filled the trees, I stopped
under an oak only a few rods from the one where the nest had been five
years