$1.00.

MORE CRITICISMS ON DARWIN, AND ADMINISTRATIVE NIHILISM.
12mo. Limp cloth, 50 cents.

MANUAL OF THE ANATOMY OF VERTEBRATED ANIMALS.
Illustrated. 12mo. Cloth, $2.50.

MANUAL OF THE ANATOMY OF INVERTEBRATED ANIMALS.
12mo. Cloth, $2.50.

LAY SERMONS, ADDRESSES, AND REVIEWS.
12 mo. Cloth, $1.75.

CRITIQUES AND ADDRESSES.
12mo. Cloth, $1.50.

AMERICAN ADDRESSES; WITH A LECTURE ON THE STUDY OF BIOLOGY.
12mo. Cloth, $1.25.

PHYSIOGRAPHY: AN INTRODUCTION TO THE STUDY OF NATURE.
With Illustrations and Colored Plates. 12mo. Cloth, $2.50.

HUXLEY AND YOUMANS'S ELEMENTS OF PHYSIOLOGY AND HYGIENE.
By T.H. HUXLEY and W.J. YOUMANS. 12mo. Cloth, $1.50.

JOHN TYNDALL'S WORKS.

ESSAYS ON THE FLOATING MATTER OF THE AIR, in Relation to
Putrefaction and Infection.
12mo. Cloth, $1.50.

ON FORMS OF WATER, in Clouds, Rivers, Ice, and Glaciers.
With 35 Illustrations. 12mo. Cloth, $1.50.

HEAT AS A MODE OF MOTION. New edition.
12mo. Cloth, $2.50.

ON SOUND: A Course of Eight Lectures delivered at the Royal
Institution of Great Britain.
Illustrated. 12mo. New edition. Cloth, $2.00.

FRAGMENTS OF SCIENCE FOR UNSCIENTIFIC PEOPLE.
12mo. New revised and enlarged edition. Cloth, $2.50.

LIGHT AND ELECTRICITY.
12mo. Cloth, $1.25.

LESSONS IN ELECTRICITY, 1875-'76.
12mo. Cloth, $1.00.

HOURS OF EXERCISE IN THE ALPS.
With Illustrations. 12mo. Cloth, $2.00.

FARADAY AS A DISCOVERER. A Memoir.
12mo. Cloth, $1.00.

CONTRIBUTIONS TO MOLECULAR PHYSICS in the Domain of Radiant Heat.
$5.00.

SIX LECTURES ON LIGHT. Delivered In America in 1872-'73.
With an Appendix and numerous Illustrations. Cloth, $1.50.

ADDRESS delivered before the British Association, assembled at
Belfast. Revised with Additions.
12mo. Paper, 50 cents.

RESEARCHES ON DIAMAGNETISM AND MAGNECRYSTALLIC ACTION, including the
Question of Diamagnetic Polarity. With Ten Plates.
12mo, cloth. Price, $1.50.

CHARLES DARWIN'S WORKS.

ORIGIN OF SPECIES BY MEANS OF NATURAL SELECTION, OR THE PRESERVATION
OF FAVORED RACES IN THE STRUGGLE FOR LIFE. From sixth and last London
edition.
2 vols., 12mo. Cloth, $4.00.

DESCENT OF MAN, AND SELECTION IN RELATION TO SEX. With many
Illustrations. A new edition.
12mo. Cloth, $3.00.

JOURNAL OF RESEARCHES INTO THE NATURAL HISTORY AND GEOLOGY OF
COUNTRIES VISITED DURING THE VOYAGE OF H.M.