hy, but after the death of the stalk the pith
contracts, and leaves the greater portion of the interior hollow, as we
have seen in the case of the cactus branches. How the birds found that
these stalks were hollow is a problem not yet solved, but, nevertheless,
they take the trouble to peck away at the hard bark, and once
penetrated, they commence to fill the interior; when one space is full,
the bird pecks a little higher up, and so continues.

Dr. Heerman, of California, describes the California _Melanerpes_ as one
of the most abundant of the woodpeckers; and remarks that it catches
insects on the wing like a flycatcher. It is well determined that it
also eats the acorns that it takes so much pains to transport.

[Illustration: FLOWER OF CEREUS GIGANTEUS.]

It seems that these birds also store the pine trees, as well as the
oaks. It is not quite apparent why these birds exhibit such variation in
habits; they at times select the more solid trees, where the storing
cannot go on without each nut is separately set in a hole of its own.
There seems an instinct prompting them to do this work, though there may
not be any of the nuts touched again by the birds. Curiously enough,
there are many instances of the birds placing pebbles instead of nuts in
holes they have purposely pecked for them. Serious trouble has been
experienced by these pebbles suddenly coming in contact with the saw of
the mill through which the tree is running. The stone having been placed
in a living tree, as is often the case, its exterior had been lost to
sight during growth.

Some doubt has been entertained about the purpose of the bird in storing
the nuts in this manner. De Saussure tells us he has witnessed the birds
eating the acorns after they had been placed in holes in trees, and
expresses his conviction that the insignificant grub which is only seen
in a small proportion of nuts is not the food they are in search of.

C.W. Plass, Esq., of Napa City, California, had an interesting example
of the habits of the California _Melanerpes_ displayed in his own house.
The birds had deposited numbers of acorns in the gable end. A
considerable number of shells were found dropped underneath the eaves,
while some were found in place under the gable, and these were perfect,
having no grubs in them.

The picture shows a very common scene in New Mexico. The columns,
straight and angular, are often sixty feet in height. It is called torch
cactus in some pl