104 
HUMMING-BIRDS. 
ing answers to my queries from the same source. Our 
materials at present to judge from are, however, very 
scanty. There is one provision apparent in the whole, 
that for warmth, — and most necessary, when we con- 
sider the small bulk of the owners to retain the animal 
heat. 
Most writers agree in the fact, that humming-birds 
lay only two eggs, but we have seen that the T. 
hirsutus lays only one. This small fecundity, with 
the many casualties which are liable to destroy them, 
the vicissitudes of season and the assaults of various 
animals, birds, and even insects, will give us some 
idea in what immense profusion these little birds exist, 
when two, or at most four, is the number of young 
reared in a season. The eggs are not so small in pro- 
portion as one would imagine on looking at the bird. 
That of the topaz-crested humming-bird is nearly | of 
an inch in length, and about f in diameter. In shape 
they are nearly a complete oval, and are pure and deli- 
cate white. The period of incubation is remarkably 
short. Latham says that the black humming-bird sits 
twelve days, and that the young leave the nest and 
follow their parents in eighteen days ; and the North 
American species, according to Audubon, hatches only 
ten days, and the young are ready to fly in one week. 
The desire to possess creatures of such beauty in a 
tame state, has induced persons often to try the ex- 
periment of keeping them in cages, though yet com- 
paratively without success. The attempts which have 
been made, however, do not preclude a possibility, by 
