These _Medusae_, as they are called, have been spoken of by many travellers, who tell us that in some parts of the sea they are so numerous that the whole ocean is covered with them, and seems to be composed of liquid fire, usually of a pale blue or green colour. The appearance is described as being of great splendour. Even in the seas on our own coasts this beautiful light is often seen. It is called phosphoric light. Something of the same kind may be seen in the carcass of a decaying fish if taken into a dark room. Not long after this, they saw flying-fish. Cook says that when seen from the cabin windows they were beautiful beyond imagination, their sides having the colour and brightness of burnished silver. When seen from the deck they did not look so beautiful, because their backs were of a dark colour. It must not be supposed that these fish could fly about in the air like birds. They can only fly a few yards at a time. They usually rise suddenly from the waves, fly as if in a great hurry, not more than a yard or two above the surface, and then drop as suddenly back into the sea as they rose out of it. The two fins near the shoulders of the fish are very long, so that they can be used as wings for these short flights. When chased by their enemy, the dolphin, flying-fish usually take a flight in order to escape. They do not, however, appear to be able to use their eyes when out of the water, for they have been seen to fly against ships at sea, get entangled in the rigging, and fall helpless on the deck. They are not quite so large as a herring, and are considered very good eating. On drawing near to Cape Horn, on the extreme south of South America, the voyagers began to prepare for bad weather, for this Cape is notorious for its storms. Few mariners approach the Horn without some preparation, for many a good ship has gone to the bottom in the gales that blow there.