On the rocks rest stalkless mushrooms, gills uppermost, which blossom as pom-pom chrysanthemums; rough nodules, boat- and canoe-shaped dishes of coral. Adhering to the rocks are thin, flaky, brittle growths resembling vine-leaves, brown and golden-yellow; goblets and cups, tiered epergnes, distorted saucers, eccentric vases, crazily-shaped dishes. Clams and cowries and other molluscs people the cracks and crevices of coral blocks, and congregate beneath detached masses and loose stones. In these fervid and fecund waters life is real, life is earnest. Here, are elaborately armoured crayfish (PALINURUS ORNATUS), upon which the most gaudy colours are lavished; grotesque crabs, fish brilliant in hue as humming-birds. Life, darting and dashing, active and alert, crawling and slithering, slow and stationary, swarms in these marine groves. A coral reef is gorged with a population of varied elements viciously disposed towards each other. It is one of Nature's most cruel battlefields, for it is the brood of the sea that "plots mutual slaughter, hungering to live." Molluscs are murderers and the most shameless of cannibals. No creature at all conspicuous is safe, unless it is agile and alert, or of horrific aspect, or endowed with giant's strength, or is encased in armour. A perfectly inoffensive crab, incapable of inflicting injury to anything save creatures of almost microscopic dimensions, assumes the style and demeanour of a ferocious monster, ready at a moment's notice to cry havoc, and let loose the dogs of war. Another hides itself as a rugged nodule of moss-covered stone; its limbs so artfully stowed away that detection would be impossible did it not occasionally betray itself by a stealthy movement. The pretty cowrie, lemon-coloured and grey and brown, throws over its shining shoulders a shawl of the hue of the rock on which it crawls about, grey or brown or tawny, with white specks and dots which make for invisibility--a thin filmy shawl of exquisite sensitiveness. Touch it ever so lightly, and the helpless creature, discerning that its disguise has been penetrated, withdraws it, folding it into its shell, and closes its door against expected attack. It may feebly fall off the rock, and simulating a dead and empty shell, lie motionless until danger is past. Then again it will drape itself in its garment of invisibility and slide cautiously along in search of its prey. Under the loose rocks and detached lumps of coral for one live there will be scores of dead shells. The whole field is strewn with the relics of perpetual conflict, resolving and being resolved into original elements. We talk of the strenuous life of men in cities. Go to a coral reef and see what the struggle for existence really means. The very bulwarks of limestone are honeycombed by tunnelling shells. A glossy black, torpedo-shaped creature cuts a tomb for itself in the hard lime. Though it may burrow inches deep