By JOHN HENRY COMSTOCK, Professor of Entomology in Cornell University, and ANNA BOTSFORD COMSTOCK, member of the Society of American Wood-Engravers. 8vo. cloth, IX.+701 pages, 797 figures in the text, and six full page plates. Nearly all of the figures were engraved especially for this work. Postpaid $4.07; net $3.75.

This handbook is designed to meet the needs of teachers in the public schools and of students in high schools and colleges.

Needham—General Biology

A book of outlines and practical studies for the general student

By JAMES G. NEEDHAM, Professor of Limnology and General Biology in Cornell University. Cloth 8vo. XIV.+542 pages; 288 figures, mostly original. Postpaid $2.00.

This book is expressly designed to help the general student obtain a comprehensive grasp of the principles of biology.

Comstock—Handbook of Nature-Study

By ANNA BOTSFORD COMSTOCK, Lecturer in Nature-Study in Cornell University. Cloth 8vo. XVIII.+938 pages, more than 1,000 illustrations. Prices, postpaid: Bound in one volume, $3.65; bound in two volumes, $4.50; Volume I., including Animal Life, $2.25; Volume II., including Plant Life, $2.25. Sample pages sent on application.

A handbook of Nature-Study for teachers and parents, based on the Cornell Nature-Study Leaflets, with much additional material and many new illustrations.

GAGE—Optic Projection