SEEING AND THINKING. By Professor W. K. CLIFFORD, F.R.S. With Diagrams. Crown 8vo. 3s. 6d.

DEGENERATION. By Professor E. RAY LANKESTER, F.R.S. With Illustrations. Crown 8vo. 2s. 6d.

FASHION IN DEFORMITY, as Illustrated in the Customs of Barbarous and Civilized Races. By Professor FLOWER. With Illustrations. Crown 8vo. 2s. 6d.

CHARLES DARWIN. Memorial Notices reprinted from Nature. By THOMAS HENRY HUXLEY, F.R.S.; G. J. ROMANES, F.R.S.; ARCHIBALD GEIKIE, F.R.S.; and W. T. THISELTON DYER, F.R.S. With a Portrait engraved by C. H. Jeens. Crown 8vo. 2s. 6d.

ON THE COLOURS OF FLOWERS. As Illustrated in the British Flora. By GRANT ALLEN. With Illustrations. Crown 8vo. 3s. 6d.

THE SCIENTIFIC EVIDENCES OF ORGANIC EVOLUTION. By GEORGE J. ROMANES, M.A., LL.D., F.R.S., Zoological Secretary of the Linnean Society. 2s. 6d.

A CENTURY OF ELECTRICITY. By T. C. MENDENHALL. Crown 8vo. 4s. 6d.

THE CHEMISTRY OF THE SECONDARY BATTERIES OF PLANTÉ AND FAURE. By J. H. GLADSTONE, Ph.D., F.R.S., and ALFRED TRIBE, F.Inst.C.E., Lecturer on Chemistry at Dulwich College. Crown 8vo. 2s. 6d.

ON LIGHT. The Burnett Lectures. By Sir GEORGE GABRIEL STOKES, M.A., P.R.S., &c., Fellow of Pembroke College, and Lucasian Professor of Mathematics in the University of Cambridge. Three Courses: I. On the Nature of Light; II. On Light as a Means of Investigation; III. On the Beneficial Effects of Light. Crown 8vo. 7s. 6d.