ispersion of plants, 621.

Smith, William, agreement of his system with Werner's, 48.
----, his "Tabular View of the British Strata," 1790, 58.
----, his map of England, 58.
----, priority of his arrangement, 58.

Smith, Mr., of Jordan Hill, on the colder climate of newest tertiary
period, 126.
----, on temple of Serapis, 516.

Smyrna, volcanic country round, 355.

Smyth, Capt. W. H., on the Mediterranean, 45, 259, 296, 511.
----, on height Of Etna, 396.
----, on Straits of Gibraltar, 333, 336.
----, on depth of sea from which Graham Island rose, 432.
----, on floating islands of drift-wood, 641.
----, on drifting of birds by the wind, 645.
----, on diffusion of insects, 657.
----, on average number of British ships lost, from 1793 to 1829,
755.
----, found shells at great depths between Gibraltar and Ceuta, 773.

Snow, height of perpetual, in the Andes, 112.
----, in Himalaya mountains, 112.
----, lowest limits of perpetual, at equator, 222.
----, lowest limits of perpetual, at Swiss Alps, 222.

Sodertelje, buried hut in canal of, 524, 528.

Soil, its influence on plants, 590.

Soils, on formation of, 709.
----, influence of plants on, 670.

Soldani, on microscopic shells of Mediterranean, 44.
----, on the Paris basin, 44.

Solent, its channel widening, 318.

Solfatara, lake of, 243.
----, volcano, 358, 363, 367, 385.

Solitaire, recently extinct bird, 684.

Solway Moss, 723.

Solway Firth, animals washed by river floods into, 760.

Somersetshire, land gained in, 324.
----, submarine forest on coast of, 323.

Somerville, Mrs., on depth of ocean, 104.

Somma, escarpment of, 381.
----, dikes of, 382.
----, supposed section of Vesuvius and, 381.

Sorbonne, College of the, 39.

Sorting power of water, 287.

South Carolina, earthquake in, 466.

South Downs, waste of plastic clay on, 317.

Spain, earthquakes in, 358.

Spallanzani on effects of heat on seeds, 621.
----, on flight of birds, 644.

Species, definition of the term, 567.
----, Linnaeus on constancy of, 568.
----, Lamarck's theory of transmutation of, 567, 580, 699.
----, reality of, in nature, 583, 591, 592, 611.
----, geographical distribution of, 612.
----, theories respecting their origin, 666, 703.
----, Brocchi on extinction of, 668.
----, reciprocal influence of aquatic and terrestrial, 676.
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