is particular individual to finish her
labors, which might be extended for hours for aught I knew, I turned my
glass upon its nearest neighbor, and a most accommodating specimen she
proved, disclosing all the mysteries of the little froth house, its
strange material, and unique method of construction. What I saw reminded
me irresistibly of the technique of the cake-frosting art of the fancy
baker, with its flowing tube of white condiment, and its following
tracery of questionable design in high relief. This accommodating
specimen had apparently just completed her egg-laying, or had perhaps
just filled one nest; and while her attitude was precisely similar to
that of her neighbor, I noticed a tiny ball of glistening froth at the
tip of the ovipositor. This was attached to the bark by a touch, and
from this starting-point the construction of the glistening house was
continued, the apex of the ovipositor pouring out its endless puffy roll
of aerated cement, which seemed to set as soon as laid.

And what a convenient implement this for a froth-house builder who is
compelled to work behind her back--mortar-feeder, trowel, darby,
compass, and level all in one! Beginning with the first touch of the
cement, the flowing point describes a very small half-circle to the
right, again meeting the bark. It is now carried inward and upward,
describing a very close circle with scarcely any space intervening, a
similar circle being repeated on the left side. A new tier is then begun
in the same manner, only this time a little larger in the sweep, and
leaving a perceptible opening at the right as the central wall is
carried upward with slightly decreased material. Returning down the
central wall again, the white coil is carried to the left along the
bark, and up again on the other outer edge, until it once more meets its
fellow at the ridge-pole, where the two coils appear to interlock as in
a braid. And thus the little builder continues, enlarging the cavity
with each circuit, until the full height is reached, and then decreasing
proportionately until the glistening braided dome is tapered off again
against the bark.

[Illustration]

Now what is the object of this frothy pavilion? The life history of the
insect, in contrast to that of the cicada, will perhaps throw a little
light on that question. In the cicada, as I have shown, the eggs are
inserted in the bark, but the young, hatching about six weeks later,
immediately forsake the p