National Geographic : 1952 Oct
numerable fins. Every one of the dorsal fins is slightly venomous, a fact which may explain why it didn't become frightened when we poked it a little. The abundance of marine life and its va riety of form and color reached a maximum between 10 and 30 feet. Here, in addition to the flashing shoals of fish, we could discern in numerable worms, small, hairy crabs, and colored slugs-a whole crowd of vermin-on holiday looking as if they had "dressed ship" for the occasion. Celery-shaped a cyo narians grew in profu sion; each deck of coral flaunted a parasol; cylindrical sponges protruded like sections of sugar cane; gorgo nian colonies developed to the size of trees; and whiplike horny coral trailed in the water like abandoned lamp cords (page 469). At 130 feet, where light and color dimin ish, Dumas and I found the scenery familiar. We had glimpsed cliffs Scientists Che like these below Cassis and Ile de Riou, off the southern coast of France. Here were the same loggias cut into the dead wall, the same tapestries of ascidians and calcareous algae. The only things we missed were the lobsters, which, in the Medi terranean, lounge on balconies like these. At 200 feet the cliff came to a halt, and a ramp of sand and mud sloped away at 45° to 500. We thought we detected at 260 feet another abrupt drop, but we decided not to flirt any further with narcosis. I found it difficult to imagine how these reefs had been built, except in terms of the Darwinian theory. Starting from a pre existing rock base, close to the surface, the corals must have begun to form toward the light. Their growth rate doubtless corre sponded with a very slow sinking of the sea bottom. As the coral gradually thickened, its base must finally have dropped to a depth where the microorganisms building it tended to die and all construction ceased. Certain parts of the reef seemed particu- 453 Jacques Ertaud ck Sediment Dredged from the Red Sea larly rich in fish. Sometimes we passed through schools so thick that we could not even see through them, much less avoid them, and against our skin we felt the tap-tap of thousands of little snouts. TNT Brings a Rain of Fish Into one such shoal Dumas dropped a 100 gram cartridge of TNT. Result: a rainfall of tiny fish, colorless and clear as glass, for 100 feet around. Another experiment brought up 200 pounds of coral fishes. Caught and spilled on the Calypso's deck, they formed a vibrant rainbow, with colors so bright and shapes so strange as to wring a gasp of ad miration from everyone aboard. After death, the colors faded and the bodies tarnished. But by color photographs, taken immediately, we were able to retain at least on film their pristine beauty (pages 466, 467). Our marine biologists, Cherbonnier and Mer cier, lost little time, however, in post-mortem eulogies; they filled up their jars.