Subterranean Dwellings.
I do not intend in this place to take up the whole subject of Subterranean Dwellings, but only to point out cases where the use of the Subterranean Dwelling depends on the climate of the locality and the time of year, it being sometimes used and sometimes neglected, sometimes inhabited for the sake of warmth, and sometimes for that of coolness.
In various parts of India there are some most remarkable Subterranean Dwellings. They are more than mere dwellings, and are, in fact, magnificent palaces, sunk so deeply in the earth that very little more than their roofs appear aboveground. When, however, a visitor descends the stairs that lead to the interior of the palace, he finds it spacious, and with tiers of chambers one below the other, very much like the wasp-nest which has already been described. Nussur-ed-deen, the second King of Oude, had several of these palaces, but very seldom visited them, he having endeavoured to Europeanise himself as much as possible, and to cast off his native customs. He used occasionally to visit them, but it was only out of etiquette, and he never really lived in them.
However much he might have rejected the ancient customs, it is evident that in this case, at least, he was punishing himself in rejecting these summer dwellings, which are always cool, and where, if one set of apartments is too warm, nothing is easier than to descend to the next.
This dwelling is made for the sake of coolness in summer. Another subterranean dwelling is made for warmth in winter, the non-conducting properties of the earth being in both cases brought into play. This is the winter dwelling of the inhabitants of Kamschatka.
During the summer-time the Kamschatdales live in comparatively slight huts mounted on poles, and having the floor some ten feet from the ground.
During the winter, however, they live in habitations of a very different character.
In order to make these houses, they begin by digging a large hole in the ground, about nine or ten feet in depth. This they line with poles and sticks, making, in fact, a wall as of a house. A stout conical roof is then raised over the hole, and upon the roof earth is thickly strewn and beaten down, just as has been mentioned when treating of the ice-house. The only access to this strange house is by a circular aperture in the centre of the conical roof, serving at once the purpose of a door, a chimney, and a window. A notched pole answers as a ladder, a low wooden dais placed against the wall serves as a bed or a chair, for there is no other, and a few stones placed together act as a fireplace.
In looking at both these subterranean dwellings, I could not but be reminded of a very common insect which has a double dwelling, one moiety being aboveground, and the other moiety below it. This is the common Wood-ant (Formica rufa), whose large, leafy hills are so plentiful in some of our woods. On account of its size, this species is sometimes called the Horse-ant.
At first sight the nest looks something like a small haycock, made entirely of chopped grass. When examined more nearly, it will be found to consist mostly of grass-stems, little bits of stick, and leaves. Those of the fir are in great request, for when they are dry they are very light, and their form enables the Ant to interweave them with each other, so as to form the necessary tunnels and galleries which line the interior of the nest. The materials seem most unpromising, but they are used with wonderful skill, such as no human fingers could equal.
After a little while a number of entrances into the nest are visible. They are almost invariably sheltered by projecting leaves, which act as porches, so that when the nest is viewed from above, they are almost entirely hidden. Each of these openings runs into one of the main galleries of the nest, and from thence issues a perfect labyrinth of passages.
This, however, is only half the nest, for the galleries and tunnels extend far beneath the surface of the earth, and have sundry enlarged portions or chambers wherein the immature pupæ may lie during their period of helplessness.
Owing to the very loose structure of the upper nest, and the tendency of the earth to fall into the galleries of the lower nest, it is very difficult to obtain a trustworthy view of the interior. Perhaps I may here be allowed to extract a passage from my “Insects at Home,” the description of the nest and its interior having been written almost on the spot:—
“I have, however, succeeded in obtaining an excellent view into the interior of a Wood-ants’ nest, though it was but a short one. Accompanied by my friend Mr. H. J. B. Hancock,[B] I was visiting some remarkably fine Wood-ants’ nests near Bagshot. We took with us a large piece of plate glass, placed it edgewise on the top of an Ant-hill, and, standing one at each side, cut the nest completely in two, leaving the glass almost wholly buried in it.
[B] Now Sir Henry J. Burford Hancock, Chief Justice of Gibraltar.
“After the expiration of a few weeks, during which time the ants could repair damages, we returned to the spot, and, with a spade, removed one side of the nest as far as the glass, which then served as a window through which we could look into the nest. It was really a wonderful sight.
“The Ant-hill was honeycombed into passages and cells, in all of which the inhabitants were hurriedly running about, being alarmed at the unwonted admission of light into their dwellings. In some of the chambers the pupæ were treasured, and these chambers were continually entered by Ants, which picked up the helpless pupæ, and carried them to other parts of the nest where the unwelcome light had not shown itself.
“Unfortunately this view lasted only a short time. Owing to the partial decomposition of the vegetable substances of which the Ants’ nest is made, the interior is always hot and always moist. Now, the day on which we visited the nest happened to be a cold one, and, in consequence, the moisture of the nest was rapidly condensed on the inner surface of the glass, and in a few minutes completely hid the nest from view, leaving me only time to make a rapid sketch. Unfortunately some one discovered the plate of glass and stole it.
“Next time that I examine a Wood-ants’ nest, I shall take care to insert the glass exactly east and west, and shall open its southern side towards noon on a hot sunshiny day, so that the rays of the sun may warm the glass and prevent evaporation.”
Many other creatures make subterranean dwellings, but the Wood-ant is remarkable for possessing a double dwelling, the two portions communicating with each other, and capable of being used according to the degree of heat required.