MOUNTAINS AND FJELDS. 115 



southern latitudes, as they are under the equator and in 

 temperate regions. Codium tomentosum, ceranrium rub- 

 ruin, C. diaphanum, species of ectocarpus, and several con- 

 ferae, have a region nearly as wide. Plocamium coccineum 

 and gelidium corneuin are common to the Atlantic and 

 Pacific oceans; rhodymenia palmata, the common dulse 

 of Britain, is found at the Falkland Islands and Tasmania. 

 Fucus tuberculatus extends from Ireland to the Cape of 

 Good Hope ; fucus vesiculosus occurs on the north-west 

 coasts of America, and on the shores of Europe; while 

 desmarestia ligulata is found in the north Atlantic and 

 Pacific oceans, as well as at the Cape of Good Hope and 

 Cape Horn. 



* In general, however, sea- weeds are more or less limited 

 in their distribution, so that different marine floras exist in 

 various parts of the ocean. The northern ocean, from the 

 pole to the 40th degree, the sea of the Antilles, the eastern 

 coasts of South America, those of New Holland, the Indian 

 Archipelago, the Mediterranean, the Red Sea, the Chinese 

 and Japanese seas, all present so many large marine 

 regi >ns, each of which possess a peculiar vegetation. The 

 degree of exposure to light, and the greater or less motion 

 of the waves, are very important in the distribution of 

 algae. The intervention of great depths of the ocean has 

 a similar influence on sea-plants as high mountains have 

 on land-plants. Laminariae are confined to the colder 

 regions of the sea; sargassa only vegetate where the 

 mean temperature is considerable. Under the influence 

 of the Gulf Stream, sargassum is found along the east coast 

 of America, as far as lat. 44 ; and the cold south polar 

 current influences the marine vegetation of the coasts of 

 Chili and Peru, where we meet with species of lessonia, 

 macrocystis, d'urvillsea, and iridaea, which are character- 

 istic of the antarctic flora. Melanospermeae, according to 

 Harvey, increase as we approach the tropics, where the 

 maximum of the species, though, perhaps, not of indivi- 

 duals, is found; rhodospermeae chiefly abound in the 

 temperate zone ; while chlorospermeae form the majority 



