INTRODUCTION. X1x

expected. The bird does not usually glide through the air with the quick darting flight of a Swallow or
Swift, but continues tremulously moving its wings while passing from flower to flower, or when taking a more
distant flight over a high tree or across a river. When poised before any object, this action is so rapidly
performed that it is impossible for the eye to follow each stroke, and a hazy semicircle of indistinctness on
each side of the bird is all that is perceptible. «The wind produced by the wings of these little birds,” says
Mr. Salvin, ‘< appears to be very considerable ; for I noticed that while an example of Cyanomyia cyanocephala
which had flown into the room was hovering over a large piece of wool, the entire surface of the wool was
violently agitated.” Although many short intermissions of rest are taken during the day, the bird may be
said to live in air—an element in which it performs every kind of evolution with the utmost ease, frequently
rising perpendicularly, flying backward, pirouetting or dancing off, as it were, from place to place, or from
one part of a tree to another, sometimes descending, at others ascending ; it often mounts up above
the towering trees, and then shoots off like a little meteor at a right angle ; at other times it quietly buzzes
away among the little flowers near the ground; at one moment it is poised over a diminutive weed, at the
next it is seen at a distance of forty yards, whither it has vanished with the quickness of thought. During
the heat of the day the shady retreats beneath the trees are very frequently visited ; in the morning and

evening the sunny banks, the verandahs, and other exposed situations are more frequently resorted to.

The foregoing remarks are from personal observation of the habits of Zrochilus Colubris ; and I have been
informed by Mr. Salvin and others that a similar action characterizes most of the species. I believe, however,
that those members of the Trochilida which are furnished with more ample wings, such as the species of the
genera doleactis, Ramphomicron, Pterophanes, and Patagona, havea very different mode of flight, move their
wings with diminished rapidity, and pass much more slowly through the air. Mr. Darwin, when speaking
of the Patagona gigas, says, “Like others of the family, it moves from place to place with a rapidity which
may be compared to that of Syrphus among Diptera, and Sphine among Moths; but whilst hovering over a
flower it flaps its wings with a very slow and powerful movement, totally different from that vibratory one,
common to most of the species, which produces the humming noise. I never saw any other bird, where the
force of its wings appeared (as in a butterfly) so powerful in proportion to the weight of its body. When
hovering by a flower, its tail is constantly expanded and shut like a fan, the body being kept in a nearly

vertical position. This action appears to steady and support the bird, between the slow movements of its

wings.”

In the intervals of flight, I believe that they not only rest in the ordinary way, but even pass some time
in sleep; at least I found that this was the case with my living birds, and that from this state of partial
torpor they were not easily aroused. In the morning and evening they were far more animated than at any
other period of the day; and they would even perform their buzzing evolutions round their cage, and sip
from their little bottle in the night-time, if a light was brought into the room. They usually sat in a moping
position, with the bill in a line with the body, or slightly elevated, after the manner of the Kingfishers. [|
never saw them hang by their feet and sleep with their heads downwards—a position which I have been

informed is sometimes assumed by Humming-Birds.

When we have compared the wings of Calliphlow amethystinus with those of Patagona gigas, we have
noticed the two extremes of development in these organs ; but many intermediate forms exist, and each

modification has doubtless an influence on the mode and power of flight. I cannot leave the subject of the