Taking the captain's observation as a hint to say something to occupy the attention of the men and myself, and so keep us from thinking of the sharks and our painful position, he proceeded to narrate all he knew about this curious marine fungus. He had a good deal to say, too, for Mr Marline was a well-read man and took a great interest in all matters of science. It was certainly a very novel situation in which to give a lecture, but the sailors were glad enough to listen to anything to make the time pass. They were very attentive auditors, even Jake appearing interested, although he could not have understood much of what he heard. "The Sargasso, or weedy, Sea," said Mr Marline, "so called from the berries, like grapes, `sarga' in Portuguese, extends from about the eleventh parallel of latitude to 45 degrees north, and from 30 degrees west longitude to the Bermudas, and even further west, so that we are about in the middle of it now. Almost the entire portion of this space of the ocean is covered by a peculiar species of sea-weed, termed by botanists the `fucus natans,' which is found nowhere else in any great abundance except in the Gulf Stream, which, skirting along the edge of the Sargasso Sea, bears away portions of the floating substance in its progress from the Gulf of Florida eastwards. The western current to the south of this region also sometimes detaches masses of the weed; but its main habitat is the Sargasso Sea, where, there being no eddies or streams either way and little or no wind generally, the sargassum accumulates in great masses, presenting frequently the aspect of an immense marine meadow." "I think, sir," I interposed at this point, "I read once in the Life of Columbus, that, when on his first voyage beyond seas from Spain, his sailors almost mutinied and wanted him to put back on account of their fancying they could never pass through the weed?" "They did," replied Mr Marline. "The men thought Columbus had sold his soul to the spirits of evil, and that they were in an enchanted sea, but the brave old Genoese navigator surmounted their fears in the end! I can better, perhaps, explain, Tom, the reason for the weed accumulating so hereabouts, by likening, as Maury did, the Atlantic Ocean to a basin. Now, if you put a few small pieces of cork or any other light substance into a basin, and move your hand round it so as to give the water it contains a circular motion, the bits of cork will be found to float to the centre and remain there. Well, here, the Gulf Stream is the circular motion of our great basin, while the Sargasso Sea is the centre, and it is in consequence of the continual current circling round it that the weed stops there in such quantities--as you will see most likely in a day or two, when the ocean gets rested after the great storm we have had, which has somewhat put things out of their proper trim." "And does the weed grow to the bottom?" I asked.