=================================================================== =GAGE--The Microscope= An Introduction to Microscopic Methods and to Histology By SIMON H. GAGE. Twelfth edition in press. Entirely rewritten, and with many new illustrations. Price $2.00. This work aims to give help to everyone who uses the microscope, whether he is a beginner or an advanced worker. =COMSTOCK--A Manual for the Study of Insects= 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= By SIMON HENRY GAGE, Professor Emeritus of Histology and Embryology in Cornell University, and Henry Phelps Gage, Ph. D. This work of over 700 pages and with over 400 figures is of especial interest to workers in all fields of Biology in that it deals especially with the use of the Projection Microscope for demonstrations and for drawing. It also gives the fundamental principles of all the forms of projection. A 16-page circular will be sent on request. Postpaid, $3.00. =RILEY--Handbook of Medical Entomology= By WM. A. RILEY, Ph. D., Professor of Insect Morphology and Parasitology in Cornell University and O. A. JOHANNSEN, Ph. D., Professor of Biology in Cornell University. A concise account of poisonous, and disease-carrying insects and their allies, including descriptions and illustrations of the principal species, with keys for their determination, and method of control. Bound Library Buckram, medium 8vo. Nearly 375 pages. Price $2.00 net.