Its use he learnt by grim experience. When first he moved it, it drove him headlong into inky darkness. His gills crumpled in the rough embrace of the mud, and his eyes and sucker were choked with slime. It was only a desperate, convulsive, aimless wriggle that freed him. The next time he cleared his immediate surroundings, and shot a full six inches upwards, only to sink slowly to the ooze again, motionless, and exhausted. He had described an elegant parabola. Day by day his excursions grew longer and higher. Nor were they without adventure. Sometimes he would be caught in the wake of a stickleback, and would reach the bottom spinning, or on his back. He was lucky to reach it at all. Sometimes a sunbeam's dazzling radiance would check him in mid-career, and his callow eyes would take an hour to recover. It was a month before his eyelids developed. Sometimes he would collide with others of his own kind, equally unskilled in steering, and sometimes a vague quiver in the water caused him instinctively to mimic death, and thus avoid death in reality. In a week's time he had grown out of all knowledge. To be accurate, he had doubled in size. But, even then, it was only the copper gleam of his eyes that saved him from utter insignificance. The remainder of him, for the most part of jelly transparency, was invisible against his sombre surroundings. His sucker had taken the semblance of a mouth, his gills were longer and more feathery, the curves of his tail were more shapely, but still he was, as yet, the merest apology for a tadpole, and so he remained until his limbs grew. They came in front at first--froggy's come behind, he wants them to swim with--the most curious spindle-shanks of arms that can be imagined, with elbows always flexed, and fingers always stretched apart. In due course his legs followed, of like purpose and absurdity. For swimming he only used his tail, but for balancing and steering, his feet and hands. Would he rise to the surface, he must flick his tail, and turn his toes and fingers upwards. Would he seek the bottom, he must depress them. Would he lie motionless, suspended in mid-water, he must point them straight outwards from his sides. [Illustration: HIS SUCKER HAD TAKEN THE SEMBLANCE OF A MOUTH.] [Illustration: HIS GILLS WERE LONGER AND MORE FEATHERY.] It was the charm of a free-swimming existence that divorced him from a vegetarian diet. To be continually sucking in plant sludge was a low grubby business at the best. Besides, he was now furnished with a respectable pair of jaws, not to mention the rudiments of teeth. Daphne was his first victim. Daphne sounds somehow floral, but this Daphne was equipped with one eye and several pairs of legs, and practised abrupt jumpy flights through the water. In short, she was a branchiopod, to be vulgarly precise, a water-flea. The succulence of Daphne led to experiments on Cyclops--Cyclops is her first cousin--and the taste, once acquired, never left him.