On the right hand, and just below the looper caterpillar, is the common Lappet-moth of this country, shown in its position of rest.
When it assumes this attitude, it looks exactly like a withered leaf, the resemblance extending not only to the form, but the colour. All entomologists are familiar with many similar examples in insect life. The common Tortoise-shell Butterfly, for example, has a way of settling on patches of red soil, with which it harmonizes so well that it can hardly be seen. The various moths, also, are in the habit of resting on tree-bark, palings, and other objects, to which they instinctively know that they assimilate in hue. Many a beginner in entomology will pass a wooden fence or a wall, and not see an insect on either, while an adept will follow him and take twenty or thirty good specimens.
The last figure in the illustration represents a Ptarmigan (Lagopus vulgaris) in its winter dress. These birds have two differently coloured dresses, one for summer and the other for winter, and both adapted for concealment by imitation. In the former dress it is mottled with various shades of blackish brown, yellow, and white. As the bird is in the habit of settling among the grey lichen-covered stones on the sides of rocky hills, these colours harmonize so exactly with them that a Ptarmigan may almost be trodden upon before it is perceived.
In the winter, when the snow covers the whole country with one uniform sheet of white, except where the wind blows the snow aside, and exposes the underlying stones, the Ptarmigan assumes a different plumage, being almost entirely white, except a black streak over the eye, and the outer feathers of the tail, which are also black. Thus the bird becomes almost indistinguishable from a snow-covered stone, especially as it has a habit of squatting motionless and silent when it takes alarm.
The reader may, perhaps, remember that the common Stoat also has a summer and winter dress. The ordinary colour is rich reddish brown above, and white beneath, with a black tip to the tail. In the severe winters of Northern Europe the Stoat exchanges his ruddy coat for one of pure white, and is then known by the name of Ermine. It is remarkable that in the winter dress both of the Ptarmigan and Stoat the tail is black, while the rest of the coat is white.
The Trench.
We now come to a third mode of concealment in war, namely, that which is obtained by means of Trenches or Pits.
Even in hunting the pit or partial trench is largely used. In Southern Africa the hunter often employs such a trench, called technically a “Skärm.” It is very simple in idea, and easily made, being based on the principle that lions, elephants, &c., look for their assailants on the level of the earth, and seldom, if ever, look above or below it. Accordingly the hunter, having marked some pool or lake whereunto the wild animals resort at night to quench their thirst, chooses a convenient spot, and there digs a trench some seven feet in length and four deep, and covers it in with stout tree-branches and logs of various size. The whole is roofed in with sods, and the only entrance is at one end.
Here the hunter sits and waits, and, as his ear is on a level with the surface of the ground, he can hear at a considerable distance sounds which would have escaped him had he been erect.
Waiting for a favourable opportunity, as the various beasts come to drink, the hunter chooses one, takes careful aim, and fires one of his heaviest guns. It is but seldom that the rest of the animals charge in the direction of the Skärm, but even if they do, the hunter is quite safe under the shelter of his strong roof, which is able to resist even the heavy tread of an elephant.