Besides this, there is always floating on top some of the remains of the booty that the crafty crab in his wandering impunity has gathered below.
Ferragut, on passing from one tank to the other, mentally established the gradation of the fauna from the primitive protoplast to the perfect organism.
The sponges of the Mediterranean swam as soon as they were born, when they were like pin-heads, with vibratory movements.

Then they remained immovable, the water filtering through the cracks and crannies of their texture, protecting their delicate flesh with a bristling of spikes,--sharp limestone needles with which they pierced the passing fishes and rendered them immovable, availing themselves of the nourishment of their putrefying remains.
The nettles of the sea spread out their stinging threads by the thousands, discharging a venom that stupefies the victim and makes him fall into their corolla.

With unlimited voracity, and fastened to the rocks, they overpower fish much larger than they, and at the first hint of danger shrink together in such a way that it is very difficult to see them.

The sea-plumes lie flabby and dark as dead animals, until absorbing water, they suddenly rear themselves up, transparent and full of leaves.

Thus they go from one side to the other, with the lightness of a feather, or, burrowing in the sand, send forth a phosphoric glow.
The belles of the sea, the elegant Medusae, open out the floating circle of their fragile beauty.