e was suspended--one upon the end of each branch--a number of
odd-shaped objects, that hung drooping down until their lower ends
nearly rested upon the surface of the water. These objects, as stated,
were of a peculiar shape. At the upper ends--where they were attached
to the branches--they were globe-shaped, but the lower part consisted of
a long cylinder of much smaller diameter, and at the bottom of this
cylinder was the entrance. They bore some resemblance to salad-oil
bottles inverted, with their necks considerably lengthened; or they
might be compared to the glass retorts seen in the laboratory of the
chemist.

They were each twelve or fifteen inches in length, and of a greenish
colour--nearly as green as the leaves of the tree itself. Were they its
fruit?

No. The weeping-willow bears no fruit of that size. They were not
fruit. They were _nests of birds_!

Yes; they were the nests of a colony of harmless finches of the genus
_Ploceus_,--better known to you under the appellation of "weaver-birds."

I am sure you have heard of weaver-birds before this; and you know that
these creatures are so-called on account of the skill which they exhibit
in the construction of their nests. They do not _build_ nests, as other
birds, but actually _weave_ them, in a most ingenious manner.

You are not to suppose that there is but one species of weaver-bird--one
kind alone that forms these curious nests. In Africa--which is the
principal home of these birds--there are many different kinds, forming
different genera, whose hard names I shall not trouble you with. Each
of these different kinds builds a nest of peculiar shape, and each
chooses a material different from the others. Some, as the _Ploceus
icterocephalus_, make their nests of a kidney-shape, with the entrance
upon the sides, and the latter not circular, but like an arched doorway.
Others of the genus _Plocepasser_ weave their nests in such a manner,
that the thick ends of the stalks stick out all around the outside,
giving them the appearance of suspended hedgehogs; while the birds of
another genus closely allied to the latter, construct their nests of
slender twigs, leaving the ends of these to project in a similar manner.
The "social gros-beak" (_Loxia socia_) fabricates a republic of nests
in one clump, and all under one roof. The entrances are in the
under-surface of this mass, which, occupying the whole top of a tree,
has the appearance of a haystack,