Smerinthus tiliae.

Smith, A.

Smith, W.

Snyder.

Sociology, Darwinism and.—History and.

Soddy.

Sollas, W.J.

Sorley, W.R.

Species, Darwin's early work on transmutation of.—geographical distribution and origin of.—immutability of.—influence on environment on.—Lamarck on.—multiple origin of.—the nature of a.—polymorphic.—production by physico-chemical means of.—and varieties.—de Vries's work on.

Spencer, H., on evolution.—on Lyell's "Principles".—on the nature of the living cell.—on primitive man.—on the theory of Selection.—on Sociology.