up the road the deer must have crossed.

When Mountain Billy and I pulled ourselves together and started after
the deer, the poor horse was so unstrung he made snakes of all the
sticks he saw and shied at all imaginable bugaboos along the way. We
were too late to see the deer again, but found the marks of its hoofs
where it had jumped a ditch and sunk so deep in the fine sand on the
other side that it had to take a great leap to recover itself.

The sight of the deer made Billy as nervous as a witch for days. Every
time we went to visit the wrens he would stand with eyes glued to the
spot where it had appeared, and when a jack-rabbit came out of the brush
with his long ears up, Billy started as if he thought it would devour
him. I was perplexed by his nervousness at first, but after much
pondering reasoned it out, to my own satisfaction at least. His name
was Mountain Billy, and in the days when he had been a wayward bucking
mustang he lived in the Sierra. Now, even in the hills surrounding our
valley, colts were killed by mountain lions. How much more in the
Sierra. Mountain lions are large fawn-colored animals: that was it:
Mountain Billy was suffering from an acute attack of association of
ideas. The sight of the deer had awakened memories of the nightmare of
his colthood days.

We made frequent visits to the wren tree, and both my nervous little
horse and I had a start one morning, for as we rode in, a covey of quail
flew up with a whirr from under the tree in front of us.

When the wren had become reconciled to us she worked rapidly, flying
back and forth with material, followed by her mate, who sang while she
was on the nest and chased away with her afterwards. Often when she
appeared in the doorway ready to go, his song, which had been just a
merry round before, at sight of her would suddenly change to a most
ecstatic love song. He would sit with drooping tail, his wings sometimes
shaking at his sides, at others raised till they almost met over his
back, trembling with the excitement of his joy. This peculiar tremulous
motion of the wings was marked in both wrens; their emotions seemed too
large for their small bodies.

I found the wrens building, the last of April. The third week in May
the little lover was singing as hard as ever. I wrote in my
note-book--"Wrens do not take life with proper seriousness, their duties
certainly do not tie them down." When the eggs were in the nest, if her
mate sang at her d