Animals, functions of the frame of, ii. 1 sarcode and muscle, ii. 2 blood, ii. 2 waste and repair, ii. 3 food, ii. 3 animal heat, ii. 3 the heart, digestion, heat, and respiration, ii. 4 nerve-force of animals, ii. 4 nervous system, ii. 5 structure and functions of the brain and spinal cord, ii. 8 intelligence, or the mental principle, in animals, ii. 11, 12 Anise seed, amount of radiant heat absorbed by the perfume of, i. 44 Annelida, characters of the, ii. 149 mode of reproduction of, ii. 160 luminosity of, ii. 160 fossil remains of, ii. 161 Annulosa, or worms, characters of, ii. 144 Anomura, structure and mode of reproduction of, ii. 197 Antennaria Robinsonii, mode of reproduction of, i. 296 Antennariei, structure of, i. 296 Anthoxanthum odoratum, or sweet-scented vernal grass, mode of reproduction of, i. 386 Anthozoa zoophytes, or living flowers, characters of, ii. 119 Antiaris toxicaria, causes of the virulence of, i. 426 fruit of, innocuous, i. 426 Antozone, i. 8 Aphrodita hystrix, structure and mode of reproduction of, ii. 159 Apolemia contorta, structure and mode of reproduction of, ii. 108, 109 Apple, fructification of the, i. 381 Apus cancriformis, structure of the, ii. 210 Aqueous vapour, i. 53 absorptive power of, i. 53-55 Arachnoidiscus Ehrenbergii, structure of, i. 199 Arcella, structure and mode of formation of the shell of, ii. 21, 22, 23 Aregma speciosum, spores of, i. 276 Arenicola, structure of, ii. 157 Arragonite, i. 108 external and internal alteration of, by heat, i. 108 Artemia salina, structure of, ii. 210 Artocarpus, or bread-fruit tree, i. 426 Arum, structure and mode of reproduction of, i. 388 water secreted by the, at night, i. 429 Arundo Donax, size of the, i. 386 Ascaris lumbricoïdes, structure and mode of reproduction of, ii. 147 Asci, or sporidia sacs, of Ascomycetes, i. 290 Ascidia virginea, structure, food, and habitat of, ii. 224, 225 Ascidians, or Tunicata, character of, ii. 222 compound or social gelatinous, ii. 222 star-like, ii. 224 Ascomycetes, structure of, i. 290 Ascophora elegans, fructification of, i. 226 Ashes, i. 14 Aspergillus dubius, spores of, i. 286 Aspergillus glaucus, spores of, i. 286 Asphalt, sources of, in various parts of the world, i. 126 Aspidieæ, characters and habitat of the group, i. 346, 348 Asplenieæ, characters and habitat of the group, i. 351, 352, 353 Asplenium lanceolatum, structure, fructification, and habitat of, i. 354 Asplenium marinum, structure and habitat, i. 355, 356 Asplenium Ruta-muraria, or wall rue, structure, habitat, and reproductive organs of, i. 353, 354 Asteroïdea, or star-fishes, characters of the, ii. 169 fossil star-fishes, ii. 174 Athyrium Filix-fœmina, or lady fern, herbaceous caudex of, i. 340 structure and fructification of, i. 352, 353