Life, unity of organic, 189; definitions of, 191; conditions essential for, 206; water essential for, 210; atmosphere for, 210; dependent on temperature, 218; now improbable in stars, 288; conditions essential for, summarised, 314. Life-processes, explanations of, 202. Light, velocity of measured, 79; necessity of solar, 209; from sky due to dust, 252. Light-journey explained, 75. Light-ratio shows stars to be limited, 152. Living bodies, essential points in, 192. Lockyer, Sir. N., on inorganic evolution, 117; on evolution of stars, 130; on Milky Way, 159; on position of solar system, 161. Luigi d'Auria on stellar motion, 306. M'Kendrick, Prof., on germinal vesicle, 202. Magnetism and sun-spots, 106. Man, Shakespeare on, 322. Mars, has no water, 266; excessive temperatures on, 267. Matter of universe uniform, 183. Maunder on dark stars, 143. Maxwell Hall, Mr., on star-motions, 178. Measurement of star-distances, 85; difficulty of, 86. Mercury not habitable, 266. Meteorites, elements in, 185; not primitive bodies, 186. Meteoritic hypothesis, 113; Proctor on, 114; explains nebulæ, 116; Dr. Roberts on, 119. Milky Way, the, 48; form of, 51, 159; description of, 52; telescopic view of, 57; stars in relation to, 59; Mr. Gore on, 60; density of stars in, 61; clusters and nebulæ in relation to, 67; probable distance of, 96; forms a great circle, 157, 162; Prof. Newcomb on, 158; probably no life in, 284; diagrams of, 300; revolution of, important to us, 307. Million, how to appreciate a, 82. Minchin, G.M., on radiation from stars, 290. Monck, Mr. W.H.S., on non-infinity of stars, 144; on uncertainty of sun's motion, 177. Moon, why no atmosphere, 263. Moon's supposed origin, 233. Motion, in line of sight, 35. Motions, imperceptible, 39. Nebulæ, with gaseous spectra, 43; in relation to Galaxy, 66; distribution of, 69; many forms of, 70; gaseous, 71; meteoritic theory of, 116; planetary and annular, 175; Dr. Roberts on spiral, 117, 174; Chamberlin on origin of, 120. Nebular hypothesis, 98, 111; objection to, 112. Newcomb, Prof. S., on star distribution, 61; on parallax of stars, 94; on stability of star clusters, 126; on scarcity of single stars, 128; on limits of star system, 138; on Milky Way, 158, 160; on solar cluster, 167; on star velocities, 171; on average small mass of stars, 285; on star-motions, 297. Newton, Sir Isaac, on sun's habitability, 9. Nichols, E.F., on heat of stars, 290. Nitrogen, its importance to life, 195. Non-habitability of great planets, 272.