Monostoma, or one-mouthed medusæ, structure and mode of reproduction of, ii. 97 Monormia, habitat and structure of, i. 212 Moon, interception of the heat radiated by the full, by the earth’s atmosphere, i. 55 its effect on the higher regions of the atmosphere, i. 55 chemical power of the moon’s light, i. 55 Moonstone, or adularia, fluorescent property of, i. 66 Moonwort, structure, and habitat of, i. 366 Morchella esculenta, the morel, i. 291 katsup made from, i. 292 Mordants for fixing dyes in cotton cloth, i. 125 Morphine, the probable narcotic principle of opium, i. 427 Mother-of-pearl, composition of, ii. 234 Motion, effect of, on molecular arrangement, i. 91 Moulds, fungus, on various substances, i. 285 Mucedines, structure of the, i. 283 the origin of all fermentation, i. 289 Mucorini, or moulds, structures of the, i. 296 habitat of the, i. 296, 297 Muriatic acid, formation of, i. 20 action of, upon ammonia, i. 120 Musci, or Mosses, structure and mode of reproduction of, i. 3 antheridia of, i. 324 sporangia of, i. 325 gemmæ or buds, i. 327 leaves of, i. 330 aquatic mosses, i. 331 peat, i. 333 uses of mosses, i. 334 Muscle, structure and functions of, ii. 2 functions of the muscles, ii. 5 electric currents formed in the muscles, ii. 7 muscular respiration, ii. 8 Mushrooms, i. 261 mycelium, or spawn, i. 262 Musk, power of absorption of radiant heat by the perfume of, i. 45 Mussel, structure of the gills of the common, ii. 230 Mycelium or mushroom spawn, i. 261, 262 Mysis, or opossum shrimps, structure of, ii. 199 Myxogastres, structure, habitat, and reproduction of, i. 269, 270 their Amœba-like motions, i. 270 N Naïs, structure and habitat of the, ii. 152, 153 Naphtha, manufacture of, i. 120 uses to which it is applied, i. 120 sources of, in various parts of the world, i. 126 naphtha procured by the distillation of petroleum, i. 127 Naphthalin, production of, i. 127 Narcotics, exciting, known to almost all people, however savage, i. 427 Navicula, structure of, i. 198 Naviculæ, spontaneous locomotion of, i. 202 Nebulæ, spectra of various, i. 158-160, 163 constitution of the, i. 163 probable existence of primordial nebulous matter according to the theories of Sir W. Herschel and La Place, i. 164 Nectria, characters of the genus, i. 295 Nectria Peziza, structure of, i. 295 Nematoid entozoa, structure and mode of reproduction of, ii. 146 Nemertes gigas, or great band worm, nervous system of, ii. 158 Neotteæ, characters of the British tribe of, i. 397, 398 Neottia Nidus-avis, structure and mode of reproduction of, i. 400 Nephrolepis tuberosa, characters and habitat of, i. 348 Nereis, structure of, ii. 157 Nereis diversicolor, mode of reproduction of, ii. 160 Nereocystis Lutkeana, structure and habitat of, i. 249