is species that the captive Jews hung their harps when they
"sat and wept by the streams of Babel." This beautiful tree casts its
waving shadow over the streams of South Africa, as well as those of
Assyria; and often is the eye of the traveller gladdened by the sight of
its silvery leaves, as he beholds them--sure indications of
water--shining afar over the parched and thirsty desert. If a Christian,
he fails not to remember that highly poetical passage of sacred writing,
that speaks of the willow of Babylon.

Now the one which grew upon the little peninsula had all these points of
interest for little Trueey--but it had others as well. Upon its branches
that overhung the water a very singular appearance presented itself.
Upon these 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
ictero