Sticta, structure of the genus, i. 304 Sticta pulmonacea, structure and habitat of, i. 304 Stilbacei, structure and habitat of, i. 283 Stomach, human, fungus in the, i. 275 Stomapoda, characters of the, ii. 198 Stomata of plants, structure of the, i. 405, 406 Stone-lilies, structure of, ii. 174, 175 Strawberry, fructification of the, i. 381 Strombus gigas, or queen conch, shell of, ii. 234 Strontium, i. 3 one of an isomeric triad with calcium and barium, i. 105 red-coloured light obtained by the combustion of, i. 133 spectrum analysis of, i. 133 spectrum analysis of the rarefied vapour of, i. 142 effect of high temperature, i. 142, 143 Strychnos nux vomica, fruit of, food for birds, i. 426 Substitution, direct or indirect, the basis of the modern doctrine of equivalents, i. 104 Succinic acid, chemical combination forming, i. 97 Sugar, production of, in plants, i. 421 Sugar-cane, size and structure of, i. 386 Sulphur, i. 16 extensive range of affinities of, i. 16 Sulphur: dimorphism and allotropism of, i. 16 combination of chlorine with sulphur, i. 20 atomic weight of, compared with that of hydrogen, i. 100, 105 its analogous properties with selenium and tellurium, i. 105 spectrum analysis of, in different temperatures, i. 144 Sulphuretted hydrogen gas, i. 16 Sulphurous acid, amount of absorption of radiant heat by, i. 41 Sun, probable cause of the light and heat of the, i. 28 probability of the periodic connection of the solar spots with magnetic phenomena, i. 30, 31 amount of force exerted by the sun’s light within the limits of the terrestrial atmosphere, i. 34 chemical action of the light of the sun, i. 56 effect of the opalescence of the atmosphere on the chemical power of the sun’s light, i. 57 Sun, spectrum of the, i. 58 thirteen terrestrial substances in the sun’s atmosphere, i. 59 metals shown by M. Kirchhoff to exist in the sun, i. 151-153 and those proved not to exist in it, i. 154 the structure of the sun in some respects still a mystery, i. 164 the luminous gaseous atmosphere of the, i. 164 mottled appearance of the photosphere of the sun, i. 164, 165 the faculæ, i. 165 the red flames or protuberances round the edge during a total eclipse, i. 165 the solar spots, i. 166 their periodicity, i. 166 appear to be influenced by the planet Venus, i. 166 Sun-rise and sun-set, causes of the bright tints at, i. 58 Surirella, mode of development of, i. 202 Synapta, structure of the genus, ii. 185 Synapta digitata, structure and habitat of the, ii. 185 Syncladei, structure of the branches of, i. 328 Syncoryna Sarsii, structure and development of zooids of, ii. 90 Synthesis, in the animal and vegetable creation, i. 96 T Tænia, or tape-worm, structure and mode of reproduction of, ii. 145 transformation of the young of, ii. 146.