not by earth, which is employed throughout the
rest of the building, but by materials of a more delicate kind, which
are, moreover, very bad conductors of heat (_b_). It is a question, in
fact, of maintaining these little chambers at an almost constant
temperature, favourable for the development of the eggs. The
substances utilised for this purpose are fragments of wood and of gum.
The Termites glue them together and thus form the walls of these
important cells.

The arrangement of the top storey (D) is also disposed with a view of
protecting the young who are the future of the city. It constitutes
the attic, situated just beneath the cupola, and contains absolutely
nothing; it simply serves to interpose beneath the summit of the
edifice and the storey below a layer of air, which is a bad conductor
of heat. The chamber devoted to the young is thus placed between two
gaseous layers, a precaution which, combined with the choice of
material, places it in the very best conditions for protection against
the alternation of cold at night and torrid heat during the day.

It is difficult to know which to admire most--the audacity and
vastness of the labour undertaken by these insects, or the ingenious
foresight by which they ensure to their delicate larvae a comfortable
youth. There can be no doubt that these animals show themselves very
superior to Man, taking into consideration his enormous size compared
to theirs, in the art of building. Pillars, cupolas, vaults--nothing
is too difficult or too complicated for these small and patient
labourers.[103]

[103] The earliest comprehensive account of the Termites and
their industries was by Smeathman in the _Philosophical
Transactions of the Royal Society_, vol. lxxi., 1781, pp.
139-192. Later they were studied by Lespes: "Recherches sur
l'organisation et les moeurs du Termite lucifuge," _Ann. des
Sci. Nat._, 4me Serie, t. v., fasc. 4 and 5, Paris,
1856. For a description of the South American Termitarium
see also Bates's _Naturalist on the Amazons_ (unabridged
edition, 1892), pp. 208-214; and for the African Termites of
Victoria Nyanza, a chapter in H. Drummond's _Tropical
Africa_, 1888, pp. 123-158; while Forbes has briefly
described them in Java, _Naturalist's Wanderings in the
Eastern Archipelago_, pp. 73, 74.

The Ants of our own lands do not yield to the Termites in this
in