The different species of Termite are not equally industrious. The _T. bellicosus_ seems to have carried the art of construction to the highest point. All the individuals of the species are not alike; there exists a polymorphism which produces creatures of three sorts: 1, the _soldiers_, recognised by their large heads and long sharp mandibles, moved by powerful muscles; it is their mission to defend the whole colony against its adversaries, and the wounds they can produce, fatal to creatures of their own size, are painful even to man; 2, the _workers_, who labour as navvies and architects, and take charge of the pupae: they form the great majority of the community; 3, the _king_ and _queen_. (Fig. 38.) To each nest there is usually only a single fertile and lazy couple. These two personages do absolutely nothing; the soldiers and the workers care for them and bring them food. They have both possessed wings, but these fall off. The queen reigns but does not govern; she lays. The king is simply the husband of the queen. The internal administration of the palace is bound up with the parts played by these three kinds of beings. [Illustration: FIG. 39.] The lofty nest, or Termitarium, constitutes a hillock in the form of a cupola. The interior arrangement is very complicated, and at the same time very well adapted to the life of the inhabitants. There are four storeys in all, covered by the general exterior walls. (Fig. 39.) The walls of the dome are very thick; at the base they measure from sixty to eighty centimetres. The clay in drying attains the hardness of brick, and the whole is very coherent. The sentinels of herds of wild cattle choose these tumuli as observatories and do not break them down. The walls of this exterior _enceinte_ are hollowed by galleries of two kinds: some horizontal and giving access from outside to all the storeys; the others mounting spirally in the thickness of the wall to the summit of the dome. When the colony is in full activity, after the construction is completed, these little passages have no further use. They served for the passage of the masons when building the cupola; and they could be utilised again if a breach should be made in the wall. At the lower part these galleries in the wall are very wide, and they sink into the earth beneath the palace to a depth of more than 1 metre 50. These subterranean passages (_c_) are the catacombs of the Termites, and have a very close analogy with those of old and populous human cities. Their origin is similar; they are ancient quarries. The insects hollowed them in obtaining the necessary clay for their labours. Later, when the rains come, they serve as drains to carry off the water which might threaten to invade the dwelling.