With my ears on the alert, and with my brow in my hands, I had to take a moment’s respite in order to gather my wits together, and then I opened the door of the right wing. A little nave, as it were, stretched out before me. Its glass vault filtered the daylight and attenuated it to a bluish and refreshingly cool half-light. My steps rang out on the flagstones. In this chamber there gleamed three aquariums, three tanks of glass, so pure that the water seemed to be standing of itself in three geometrical blocks. The aquariums on the two sides of the hall held marine plants which did not seem to differ much one from the other. However, the rotunda had taught me with what method Lerne classified everything, and I could not believe that he had separated into two tanks things absolutely identical. So I watched the sea-weeds attentively. Their tufts, on both sides of the place, formed the same submarine landscape. On the right, as on the left, arborescences of every color had fixed their rigid and bifurcated stems on the rocks; the sandy bottom was sprinkled with stars like edelweiss, and here and there sprung up sheaves of chalky rods, at the end of each of which a sort of fleshy chrysanthemum unfolded itself like a yellow or a violet flower. I cannot describe the host of other _corollæ_; they often resembled oily _calices_ of wax or of gelatine; most of them showed an indefinable color in a vague outline, and sometimes they had no edges and were mere _nuances_ in the midst of the water. Bubbles escaped in thousands from an inside tap, and their tumultuous pearls raced madly along the foliage before they rose to burst on the surface. One would have thought, seeing them, that that aquatic garden had always to be drenched with air. Recalling my schoolboy memories I grasped that the two sets of flowering things--differing merely in detail--were exclusively composed of _polypi_, those ambiguous creatures, such as coral or sponge, which the naturalist interpolates between vegetables and animals. Their peculiar ambiguity is never devoid of interest. I tapped the left-hand trough. Immediately an unexpected thing moved before me swimming by means of contraction; it was like an opaline Venetian goblet which had remained malleable; a second crossed over the first; they were two jelly-fish. Meanwhile the tapping of my fingers had set other things moving. The yellow and purple tufts of the anemones went back into their calcareous sheaths, then rhythmically unfolding, emerged again; the rays of the star-fish and sea-urchins stirred lazily; grays and reds and saffrons swayed about, and, as if under the influence of an eddy the whole aquarium became alive. I tapped on the right-hand trough. Nothing budged.