40 DIVISION I. VERTEBRAL ANIMALS. —CLASS II. AVES. 
space barely sufficient for them to move their wings, they will keep their 
bodies in the air, apparently motionless, for hours together. There are, how- 
ever, exceptions to this rule. Mr. Darwin, describing the Trochilus gigas, 
which, as he observed, had arrived in the neighborhood of Valparaiso in 
numbers a little betore the vernal equinox, adds, — 
“Tt comes from the parched deserts of the north, probably for the purpose 
of breeding in Chili. When on the wing, the appearance of this bird is 
singular. Like the others of the genus, it moves from place to place with a 
rapidity, which may be compared to a syrphus amongst dipterous insects, 
and a sphinx amongst the moths ; but whilst hovering over a flower, it flaps 
its wines with a slow and very powerful movement, totally different from 
that vibratory one, common to most of the species, which produces the hum- 
ming noise. I never saw any other bird the force of whose wings appeared 
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 sup- 
port the bird between the slow movements of its wings. Although flying 
from flower to flower in search of food, its stomach generally contained 
abundant remains of insects, which, I suspect, are much more the object of 
its search than honey is. The note of this species, like that of nearly the 
whole family, is extremely shrill.” 
These brilliant creatures are an intrepid, daring race, and extremely pug- 
nacious, and cannot endure the approach of one even of their own species, 
still less of any other bird, near their breeding-places. Of one minute but 
beautiful species, the Mexican Star, Mr. Bullock says, — 
“When attending their young, they attack any bird, indiscriminately, that 
approaches the nest. Their motions, while under the influence of anger or” 
fear, are very violent, and their flight rapid as an arrow. The eye cannot 
follow them, but the shrill, piercing shriek which they utter on the wing, 
may be heard when the bird is invisible. They attack the eyes of the 
larger birds, and their sharp, needle-like bill is a truly formidable weapon in 
this kind of warfare. Nothing can exceed their fierceness when one of their 
own species invades their territory during the breeding-season: under the 
influence of jealousy they become perfect furies, their throats swell, their 
crests, tails, and wings expand, they fight in the air, uttering a shrill noise, 
till one falls exhausted to the ground.” 
It would appear, from Mr. Bullock’s statement, that Humming Birds often 
avail themselves of the insects caught in spiders’ webs; not, however, with- 
out the spiders endeavoring, not to devour, but to drive them away. “The 
house,” he writes, “I resided in at Xalapa for several weeks on my return 
to Vera Cruz, was only one story high, enclosing, like most of the Spanish 
a 
