resting fly.

The whole tribe of Ichneumon are celebrated for their courage; a small
fly will not hesitate to attack the largest cockroach, who evinces the
greatest terror at sight of his well-known enemy; but the greatest
proof of valor in a fly is displayed in the war of the ichneumon
against the spider.

There is a great variety of this insect in Ceylon, from the large black
species, the size of the hornet down to the minute tinsel-green fly, no
bigger than a gnat; but every one of these different species wages
perpetual war against the arch enemy of flies.

In very dry weather in some districts, when most pools and water-holes
are dried up, a pail of water thrown upon the ground will as assuredly
attract a host of mason-flies as carrion will bring together
"blow-flies." They will be then seen in excessive activity upon the wet
earth, forming balls of mud, by rolling the earth between their fore
feet until they have manufactured each a pill. With this they fly away
to build their nest, and immediately return for a further supply.

The arrangement of the nest is a matter of much consideration, as the
shape depends entirely upon the locality in which it is built: it may
be in the corner of a room, or in a hole in a wall, or in the hollow of
a bamboo; but wherever it is, the principle is the same, although the
shape of the nest may vary. Everything is to be hermetically sealed.

The mason-fly commences by flattening the first pill of clay upon the
intended site (say the corner of a room); she then spreads it in a thin
layer over a surface of about two inches, and retires for another ball
of clay. This she dabs upon the plastic foundation, and continues the
apparently rude operation until some twenty or thirty pills of clay are
adhering at equal distances. She then forms these into a number of
neat oval-shaped cells, about the size of a wren's egg, and in each
cell she deposits one egg. She then flies off in search of spiders,
which are to be laid tip in stores within the cells as food for the
young larvae, when hatched.

Now the transition from the larva to the fly takes place in the cell,
and occupies about six weeks from the time the egg is first laid; thus,
as the egg itself is not vivified for some weeks after it is deposited,
the spiders have to be preserved in a sound and fresh state during that
interval until the larva is in such an advanced stage as to require
food.

In a tropical country every one k