278 BACKBONED ANIMALS. 
mon in the United States, and seem to seek the company 
of human beings. The nest is formed of twigs glued with 
saliva to the chimney, forming a bracket and hardening 
co the cunsistency of stone. They drink, bathe, and eat 
on the wing, after the fashion of the humming-birds. 
Va.Lure.—The nests of the edible species are valued at fifteen or 
twenty dollars per pound in China, 
The Humming-Birds (77ochilide) are confined ex- 
clusively to America, and generally the tropical regions, 
several species being found as far west as Juan Fernandez, 
and a few species in North America. The bill is gener- 
ally long, straight or curved, the tongue capable of great 
protrusion, wings long and powerful, and claws minute 
and sharp. They are the smallest and most brilliantly 
colored of all birds. Our best-known form is the ruby- 
throat * ( Z77ochilus colubris), which attains a length of three 
and a quarter inches. 
‘Order XII. Perching Birds (asseres). General 
Characteristics —The birds of this large order have the 
feet adapted for grasping, one toe extending backward. 
The bill is sharp, horny, and generally conical. They com- 
prise the singers, and many are wonderfully musical, the 
notes corresponding to our vocal expressions.t 
* They nest in Massachusetts about the 8th of June. The nests, 
as are those of almost the entire family, are adapted to the general 
surroundings in color, and so protected. They are often attached to an 
apple-tree, made up of matted layers of flying seed-wings, and lined 
with the down of the mullein. The outside is covered with bits of 
lichen, glued on, so that the nest resembles a part of*the limb. 
+ It has been shown that young singing birds, as a rule, learn (as do 
children) the language or note of the parent that brings them up. The 
_prolonged and convulsive laughter of man is equally as ridiculous, 
when seriously considered, as the chattering of a monkey, or the so- 
called laughter of some birds. It is merely a relief from mental strain. 
(For experiments with young song-birds brought up by other parents, 
see “ Philosophical Transactions,” vol. Ixiii, by Hon. Daines Barring- 
