different kinds of ant-eaters are thus adapted to various modes
of life, terrestrial and arboreal. Those which live on trees are
again either diurnal or nocturnal, for Myrmecophaga tetradactyla
is seen moving along the main branches in the daytime. The allied
group of the Sloths, which are still more exclusively South
American forms than ant-eaters are, at the present time furnish
arboreal species only, but formerly terrestrial forms of sloths
also existed, as the Megatherium, whose mode of life was a
puzzle, seeing that it was of too colossal a size to live on
trees, until Owen showed how it might have obtained its food from
the ground.

In January the orange-trees became covered with blossom, at least
to a greater extent than usual, for they flower more or less in
this country all the year round--and attracting a great number of
hummingbirds. Every day, in the cooler hours of the morning, and
in the evening from four o'clock until six, they were to be seen
whirring about the trees by scores. Their motions are unlike
those of all other birds. They dart to and fro so swiftly that
the eye can scarcely follow them, and when they stop before a
flower, it is only for a few moments. They poise themselves in an
unsteady manner, their wings moving with inconceivable rapidity,
probe the flower, and then shoot off to another part of the tree.
They do not proceed in that methodical manner which bees follow,
taking the flowers seriatim, but skip about from one part of the
tree to another in the most capricious way. Sometimes two males
close with each other and fight, mounting upwards in the
struggle, as insects are often seen to do when similarly engaged,
and then separating hastily and darting back to their work. Now
and then they stop to rest, perching on leafless twigs, where