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. The Comstock Publishing Company Cornell Heights, Ithaca, N. Y. =================================================================== Choice Mineral Specimens It affords this establishment pleasure to state that though we are over fifty years old we are still seeking with youthful energy new finds of choice mineral specimens. A few of our recent additions will show from what widely distributed areas we draw: =Japan=: =Chalcopyrite= in groups of sharp crystals, some of them beautifully iridescent. =Stibnite=, brilliant crystals, 5 to 8 inches long. =Hokutolite=, a new radio-active barium-lead silicate. =Reinite=, in large, sharp crystals. =Quartz Twins=, fine, large crystals. =Rhodesia=: =Malachite=, beautiful polished specimens showing concentric banding. =Hopeite=, in small groups of excellent crystals. =Madagascar=: =Betafite=, a new uranium niobate, in good crystals. =Euxenite=, good crystals. =Beryl=, in large brown crystals with pyramidal faces. =California=: =Tourmaline=, polished transverse sections of large crystals of rich red and green colors. =Kunzite=, superb gem crystals.