One of those charming plain-speaking children we sometimes meet with lately said to M. Figuier, "They tell me thou art a vulgariser of Science. What is that?" He took the child in his arms, and carried it to the window, where there was a beautiful rose-tree in blossom, and invited it to pull a rose. The child gathered the perfumed flower, not without pricking itself cruelly with the spines; then, with its little hands still bleeding, it went to distribute roses to others in the room. "Thou art now a vulgariser," said he to the child; "for thou takest to thyself the thorns, and givest the flowers to others!" The parallel, although exaggerated, is not without its basis of truth, and was probably suggested by the criticism some of his works have met with; the critics forgetting apparently that these works are an attempt to render scientific subjects popular, and attractive to the general reader. * * * * * In the present edition of "THE OCEAN WORLD" it is only necessary to add to the above (dated January, 1868), that the work has been revised throughout, and some not unimportant errors corrected. For several of these I am indebted to Mr. C. O. G. Napier, who has rearranged the whole of the Mollusca. Mr. David Grieve has kindly revised and added to the Crustacea; and to the Messrs. Johnston of Montrose, and Dr. Wilson Johnston of the Bengal service, I am indebted for some valuable practical information respecting the salmon and the various modes of taking it. W. S. O. _March 1, 1869._ CONTENTS. CHAPTER I. PAGE THE OCEAN 1 Depth of the Sea 5 Colour of the Ocean 11 Phosphorescence 13 Saltness of the Sea 15 CHAPTER II. CURRENTS OF THE OCEAN 27 Trade-winds 28 Gulf Stream 31 Storms 32 Tides 35 Polar Seas 43 Antarctic Seas 50 CHAPTER III. LIFE IN THE OCEAN 60 CHAPTER IV. ZOOPHYTES 68 Foraminifera 87 Infusoria 97 CHAPTER V. POLYPIFERA 116 CHAPTER VI. CORALLINES 119 Tubiporinæ 120 Gorgoniadæ 121 Isidians 124 CHAPTER VII. ZOANTHARIA 147 Madreporidæ 149 Porites 162 Actiniaria 181 Minyadinians 193 CHAPTER VIII.