he bottom of the pool (it was too small to be called a pond) was muddy, with here and there a thicket of rushes or arrow-weed stems. Down upon the windless surface streamed the noon sun warmly. Under its light the bottom was flecked with shadows of many patterns,—circular, heart-shaped, spear-shaped, netted, and barred. There were other shadows that were no more than ghosts of shadows, cast by faint, diaphanous films of scum which scarcely achieved to blur the clear downpour of radiance, but were nevertheless perceived and appreciated by many of the delicate larval creatures which made a large part of the life of the pool.

For all its surface tranquillity and its shining summer peace, the pool was thronged with life. Beneath the surface, among the weeds and stalks, the gleams and shadows, there was little of tranquillity or peace. Almost all the many-formed and strange-shaped inhabitants of the pool were hunting or being hunted, preying or being preyed upon,—from the goggle-eyed, green-throated bullfrog under the willow root, down to the swarming animalculÆ which it required a microscope to see. Small crawling things everywhere dotted the mud or tried to hide under the sticks and stones. Curled fresh-water snails moved up and down the stems of the lilies. Shining little black water-bugs scurried swiftly in all directions. In sheltered places near the surface, under the leaves, wriggled the slim gray larvÆ of the mosquitoes. And hither and thither, in flickering shoals, darted myriads of baby minnows, from half an inch to an inch and a half in length.

In a patch of vivid sunshine, about six inches from a tangle of arrow-weed stems, a black tadpole lay basking. Light to him meant not only growth, but life. Whenever, with the slow wheeling of the sun, the shadow of a lily leaf moved over him, he wriggled impatiently aside, and settled down again on the brightest part of the mud. Most of the time he seemed to be asleep; but in reality he was keeping that incessant sharp lookout which, for the pool-dwellers, was the price of survival.

Swimming slowly up toward the other side of the arrow-weed stems, came a fantastic-looking creature, something more than an inch and a half in length. It had a long, tapering, ringed and armoured body, ending in a spine; a thick, armoured thorax, with six legs attached; and a large head, the back of which was almost covered by two big, dully staring globes of eyes. The whole front of its head—part of the eyes, and all the face—was covered by a smooth, cleft, shieldlike mask, reaching well down under the breast, and giving the creature an expression both mysterious and terrible. On its back, folded close and obviously useless, were rigidly encased attempts at wings.

The little monster swam slowly by the motion of its long and strong legs, thrusting out two short, hornlike antennÆ over the top of its mask. It seemed to be eyeing a snail-shell on a stem above, and waiting for the snail's soft body to emerge from the citadel; when on a sudden, through the stems, it caught sight of the basking tadpole. Instantly it became motionless, and sank, like a waterlogged twig, to the level of the mud. It crept around, effacing itself against the brown and greenish roots, till it was just opposite the quarry. Then it sprang, propelling itself not only by its legs, but by the violent ejection of a little stream of water from the powerful breathing-valves near its tail.

The tadpole, as we have seen, was not asleep. With a convulsive wriggle of its tail it darted away in a panic. It was itself no mean swimmer, but it could not escape the darting terror that pursued. When the masked form was almost within reach of its victim, the mask dropped down and shot straight out, working on a sort of elbow-shaped lever, and at the same time revealed at its extremity a pair of powerful mandibles. These mandibles snapped firm hold of the victim at the base of its wriggling tail. The elbow-shaped lever drew back, till the squirming prize was held close against its captor's face. Then with swift jets from the turbine arrangement of its abdominal gills, the strange monster darted back to a retreat among the weed stems, where it could devour its prey in seclusion.

Under those inexorable jaws the tadpole soon disappeared and for a few minutes the monster rested, working its mandibles to and fro and rubbing them with its front legs before folding back that inscrutable mask over its savage face. Presently a plump minnow, more than an inch long, with a black stripe along its bronze and silver sides, swam down close by the arrow-weed stems. The big eyes of the monster never moved. But, suddenly, out shot the mask once more, revealing the face of doom behind it; and those hooked mandibles fixed themselves in the belly of the minnow. Inexorable as was the grip, it nevertheless for the moment left unimpeded the swimming powers of the victim; and he was a strong swimmer. With lashing tail and beating fins, he dragged his captor out from among the weed stems. For a few seconds there was a vehement struggle. Then the minnow was borne down upon the mud, out in the broad sheen where, a little before, the tadpole had been basking. Clutching ferociously with its six long legs, the conqueror crawled over the prey and bit its backbone in two.

Swift, strong, insatiably ravenous, immeasurably fierce, the larva of the dragon-fly (for such the little monster was) had fair title to be called the wolf of the pool. Its appearance alone was enough to daunt all rivals. Even the great black carnivorous water-beetle, with all its strength and fighting equipment, was careful to give wide berth to that dreadful, quick-darting mask. Had these little wolves been as numerous as they were rapacious, there would soon have been left no life at all in the pool but theirs and that of the frogs. Between these there would have been a long and doubtful struggle, the frogs hunting the larvÆ among the weed stems, and the larvÆ devouring the tadpoles on their basking-grounds.

It chanced that the particular larva whose proceedings we have noted was just on the eve of that change which should transport it to the world of air. After eating the minnow it somehow failed to recover its appetite, and remained, all the rest of the day and through the night, clinging to one of the weed stems. Next morning, when the sun was warm on the pool, it crawled slowly up, up, up, till it came out into a new element, and the untried air fanned it dry. Its great round eyes, formerly dull and opaque, had now grown transparent, and were gleaming like live jewels, an indescribable blend of emerald, sapphire, and amethyst. Presently its armour, now for the first time drying in the sun, split apart down the back, and a slender form, adorned with two pairs of crumpled, wet wings, struggled three-quarters of its length from the shell. For a short time it clung motionless, gathering strength. Then, bracing its legs firmly on the edges of the shell, it lifted its tail quite clear, and crawled up the weed a perfect dragon-fly, forgetful of that grim husk it was leaving behind. A few minutes later, the good sun having dried its wings, it went darting and hurtling over the pool, a gemlike, opalescent shining thing, reflected gloriously in the polished mirror beneath.

The Little Wolf of the Air