Snow, the, preservation of the germ of life in seeds and roots, 32; its composition, 32, 33; the reason of its preservative qualities, 34; in the form of crystals, 34; a reflector of light, 37; its utility to the agriculturist, 37; in the polar regions, 38, 39; red snow, _which see_. Snow-bunting, the, description of, 66, 67; its favourite localities, 67, 68. Snow, perpetual, the line of, where situated, 47; its variations, 48. Snow-flea, the, its discovery narrated, 72, 73; its generic characters, 74. Soapwort, the, described, 378; its juice, 378, 379. Soil, effect of temperature upon, 317; cultivation of, 318-320; plants appropriate to different kinds of, 320, 321. _Solanum nigrum_, the, described, 82-85. Solar corona, the, nature of, 409-412. Solar eclipse of 1870, the, considered, 407-412. Solstices, the summer and winter, 45. Somerville, Mrs, quoted, 289. Sowerby, Mr, on the _Mercurialis annua_, 78. Species, number of vegetable, 339, 340, 347, 348; number of animal, 356. Spencer, Edmund, the poet, quoted, 2. Spring, the awakening of, described, 127-131. _Staphylium olens_, described, 271-273. Stars, the, their infinite number, 4; their diurnal movement, 15-17; coloured, 412-417. Stellaria, the, characteristics of, enumerated, 378. Strickland, Miss, on the legend of the forget-me-not, 240. Struve, Otto, his computation of the number of the stars, 25, 26. Sun, the, movements of, in the heavens, 292-296; length of its radius, 296, 297. Sweetbriar, the, celebrated by Spenser, Milton, Scott, and Drayton, 380; by Shakespeare, 381. Taylor, Jeremy, on carnations, 371. Telescopes, importance of their invention to science, 26. Temperate zones, the, reference to, 45. Temperature, effect of, on soil, 317. Tennyson, Alfred, the poet, quoted, 6, 7, 57, 183, 247, 319. Theophrastus, an ancient writer, on the _Agrostis_, 95. Thomson, James, the poet, quoted, 32, 100. Thought, freedom of, asserted, 311; indestructibility of, 392. Toaldo, the Italian meteorologist, his researches into the phenomena of climate, 31. Tournefort, the naturalist, his description of the _Solanum nigrum_, 84, 85, 87; quoted, 96, 234; on the medical properties of the daisy, 147. Tragus, the botanist, his account of the _Solanum nigrum_, 86. _Triticum repens_, the, described, 93. Tschudi, M., the naturalist, his description of a red-billed crow, quoted, 69, 70. Tulip, the, described, 152, 153; its introduction into Europe, 153; its cultivation, 154, 155. Twilight, phenomena of, 205. Vertebrata, the, orders of, 362. Vole, the Arctic. _See_ ARCTIC VOLE.