INDEX OF SUBJECTS 



325 



Mussel beds [coiit.) 



culture, 184 



density of, 176 



transplantation, 185 

 Mytilidae, 102 



Mytilus larvae in Baltic, 167 

 Myxosporidia, 225 

 Myxotrophic animals, 225 



Nansen-Pettersson water bottle, 7 



Naples Bay plankton, 204 

 carbon compounds in, 217 

 nitrogen compounds in, 217 



"Nasse," 23 



National Expedition, 135 

 Navicula, 230 

 Nekton, 56 

 Neritic deposits, 3i 

 Neritie plankton, 154, 156 

 Nitrogen compounds 

 added to sea, 2yl 

 in Baltic, 215 



density of plankton, and, 235 

 destroyed in sea, 291 

 estimation of, 214 

 Holstein lakes, in, 235 

 law of minimum, and, 236 

 Naples Bay, in, 215 

 North Sea, in, 215 

 produced by electric discharges, 



290 

 sea, in, 212 

 Nitrogen in atmosphere, 273 

 circulation of, 274 

 taken from N. European Seas, 289 

 taken from North Sea, 289 

 Nitrogenous land drainage, 235 



excretions, 223, 275 

 Nitre-beds, 265 

 Nitre-deposits, 292 

 Nitrification, 266, 278 

 Nitrifying bacteria, 265 

 Nitrobacter, 265 

 Nitrococcus, 265 

 Nitrosomonas, 265 

 Noctiluca, 75 



phosphorescence of, 259 

 Nordsee Expedition of 1895, 168, 199 

 cod eggs taken in, 310 

 methods of, 169 

 North Atlantic, circulation of, 42 



isotherms in, 52 

 North Cape current, 49 

 Northern neritic plankton, 154 

 North Europe, climate of, 53 

 North fishes, 248 

 North Sea, 33 

 colour of, 41 

 circulation in, 48 

 depth of, 33 



North Sea [cont.) 



European stream in, 47 



fish eggs in, 167 



fisheries of, 107 



line fisheries, 247 



plankton of, 154, 159, 309 



productivity of, 180 



temperature of, 48 



transparency of, 205 



trawling in, 197 



under currents in, 48 



water-level of, 48 

 North- Western fishing grounds, pro- 

 ductivity of, 181 

 Nuclear division, 302 

 Nutrition, modes of, 221 



Ocean, age of, 315 



bed, primitive, 300 



deposits, area of, 304 

 Oceanographical apparatus, 2 



methods, 2 



research, 2 

 Offshore plankton, 148 

 Oikopleura albicans, 139 

 Organic matter, decomposition of, 279 

 Organised food-stuffs, 210 

 Ova of dogfishes, 66 



skates and rays, 66 

 Oxygen in sea, 213, 219 



Naples Bay, in, 219 

 Oyster, chemical composition, 190 



culture, 179 



fisheries, 115 



Pacific ocean, transparency of, 41 

 Palaeochemistry of sea, 299 

 Pandalus, 108 

 Parasites, internal, 228 

 Pearl oysters, 102 

 Pec ten, eyes of, 250 

 PenicilUum in sea, 257 

 Peptones, 262 

 Peridinians 



chemical composition, 189 



density in Baltic, 164 



density in North Sea, 164 



phosphoric acid, and, 238 

 Petersen-Hensen net, 128 

 Phosphatic nodules, 292 

 Phosphorescence in sea, 259 



due to Ceratium, 259 



due to Noctiluca, 259 

 Phosphoric acid in sea, 212, 217 



and law of minimum, 236 

 Photobacillns, 259 

 Photobacteria, 259 

 Photo-chemical reactions in Suberites, 



250 

 Photosynthesis, 223, 226, 249 

 Phototropism, 248 



21—3 



