ve no trace of it.

At first sight one is tempted to regard this snowy substance as of a
different material to the rest of the nest. But does the Mantis really
employ two secretions? No. Anatomy, in the first place, assures us of
the unity of the materials of the nest. The organ which secretes the
substance of the nest consists of cylindrical tubes, having a curious
tangled appearance, which are arranged in two groups of twenty each.
They are all filled with a colourless, viscous fluid, which is precisely
similar in appearance in all parts of the organ. There is no indication
of any organ or secretion which could produce a chalky coloration.

Moreover, the method by which the snowy band is formed rejects the idea
of a different material. We see the two caudal appendices of the Mantis
sweeping the surface of the foamy mass, and skimming, so to speak, the
cream of the cream, gathering it together, and retaining it along the
hump of the nest in such a way as to form a band like a ribbon of icing.
What remains after this scouring process, or what oozes from the band
before it has set, spreads over the sides of the nest in a thin layer of
bubbles so fine that they cannot be distinguished without the aid of a
lens.

We often see a torrent of muddy water, full of clay in suspension,
covered with great streaks and masses of foam. On this fundamental foam,
so to call it, which is soiled with earthy matters, we see here and
there masses of a beautiful white foam, in which the bubbles are much
smaller. A process of selection results from variations in density, and
here and there we see foam white as snow resting on the dirty foam from
which it is produced. Something of the kind occurs when the Mantis
builds her nest. The two appendices whip the viscous secretion of the
glands into foam. The lightest portion, whose bubbles are of the
greatest tenuity, which is white on account of its finer porosity, rises
to the surface, where the caudal filaments sweep it up and gather it
into the snowy ribbon which runs along the summit of the nest.

So far, with a little patience, observation is possible and yields a
satisfactory result. It becomes impossible in the matter of the complex
central zone, where the exits for the larvae are contrived through the
double series of overlapping leaves. The little I have been able to
learn amounts to this: The end of the abdomen, deeply cleft in a
horizontal direction, forms a kind of fork, of which th