Page:The Zoologist, 4th series, vol 3 (1899).djvu/498

468 taking them up." The difficulty in cognizing the phenomenon of active mimicry is no greater than that experienced in endeavouring to explain the derivation, or evolution, of active means of defence, in fact it is much less formidable; for it is easy to comprehend even from our own experience that concealment is frequently a need, and is an art capable of cultivation and improvement. But many of the means of animal defence are in themselves almost inscrutable; we see the weapon used, but cannot account for its present existence. Natural selection may explain the improvement and survival of such useful organs, but their origin is still obscure. We will briefly allude to a few in order to make our comparison clear. The Horned Lizard (Phrynosoma sp.), commonly known as the "Californian Toad," possesses the power of ejecting jets of blood from the eyes, apparently as a means of defence. The Sand Shrimp (Crangon vulgaris) can suddenly raise a perfect cloud of fine sand round itself—"firing, so to speak, a 'broadside for the sake of the smoke,' and literally throwing dust in the eyes of his enemies." The well-known instance of the "Cuttle-fish," which is able to discharge its inky secretion, and escape, like a diplomatist, in the darkness thus effected, is another illustration, as is also the Bombardier Beetle (Pheropsophus sp.), which when caught explodes its abdominal artillery, producing sound, smoke, and pain alike. The larva of the Puss Moth (Cerura vinula) can squirt a fluid—formic acid—when handled. The common Partridge will "feign itself wounded and run along the ground fluttering and crying before either dog or man, to draw them away from its helpless unfledged young ones." Sometimes the indications of intelligent action may be almost inappreciable to our untrained cognitions in animal psychology, but even then the loosely used, and still more vaguely understood term, instinct, would have to be applied. At other times volition seems to be influenced by environment. Humboldt relates that "in the Missions of the Orinoco, and on the banks of the river Amazon, the Indians who