BIOLOGICAL SPECIALTIES Our staff is made up of Biologists. We specialize along Biological lines, and we limit ourselves to these lines. CATALOGS Now Ready 2. LIFE HISTOR- 3. MATERIALS Live and preserved animals and plants. Also Embryologi Ready in May, 1919 Skins, mounts, 2. LANTERN SLIDES 2. FOSSILS AND cal material of 3. APPARATUS FOR We are at your service: Many Biologists are THE CHICAGO BIOLOGICAL SUPPLY HOUSE Our Laboratory Spectrometers Are sold in competition with instruments of European make WM. GAERTNER AND CO. Physical and Astronomical Instruments 5345-49 Lake Park Avenue CHICAGO Complete, Conveniently Arranged, Thoroughly Free to Persons in Charge of Laboratories-to others, a SCIENTIFIC MATERIALS Co. PITTSBURGH, PA. "Everything For the Laboratory" The instrument has a very nearly uniform scale, obtained by properly proportioning the coils. It may be used as a mutual inductance. It has a good ratio of maximum to minimum inductance (about 9 to 1) and also has as high a time constant as is consistent with good design and moderate size. The instrument is fully described in Bulletin No. 152, a copy of which will be sent upon request. A New Book of Great Importance VITAL STATISTICS An Introduction to the Science of Demography By GEORGE CHANDLER WHIPPLE, Professor of Sanitary En- Physicians, health officers and all others interested in this most important branch of the municipal government will welcome the appearance of this book. It tells what statistics are and what they are not; shows how to express vital facts by figures; how to tabulate and display them by diagrams; how to compute birth- and death-rates; how to analyze a death-rate; how to adjust and standardize death-rates, and how to make life tables. xii+517 pages. 4 by 7. 63 figures. Flexible "Fabrikoid" binding. $4.00 net. JOHN WILEY & SONS, Inc. 432 Fourth Avenue NEW YORK CITY Our release from this service is of course gradual. Write for complete catalog of our revised microscope Bausch & Lomb Optical C. 409 ST. PAUL STREET ROCHESTER, N.Y. New York Washington Chicago San Francisco INSTRUCTION July 2 to August 12, 1919 SUPPLY Open the Entire Year Facilities for reseach in Zoology. Embryology, Physiology and Botany. Seventy-six private laboratories, $100 each for not over three months. Thirty tables are available for beginners in research who desire to work under the direction of members of the staff. The fee for such a table is $50.00. Courses of laboratory instruction with lectures are offered in Invertebrate Zoology, Protozoology. Embryology, Physiology and Morphology and Taxonomy of the Algae. Each course requires the full time of the student. Fee, $50. A lecture course on the Philosophical Aspects of Biology and Allied Sciences is also offered. Animals and plants, preserved, living, and in embryonic stages. Preserved material of all types of animals and of Algae, Fungi, Liverworts and Mosses furnished for classwork, or for the museum. Living material furnished in season as ordered. Microscopic slides in Zoology, Botany, Histology, Bacteriology. Price lists of Zoological and University of Manitoba Winnipeg, Canada The Board of Governors invite applications for the following appointments: Assistant Professor of Chemistry, with special qualifications in Physical Chemistry. Initial salary for this grade of appointment, $2100. (Applications in this instance from candidates who stipulate a minimum salary up to $2500 will be considered.) Lecturer in Botany to assist generally in the work of the department and carry on research. Initial salary, $1600. Lecturer in Zoology, to assist generally in the work of the department and carry on research. Initial salary, $1600. Assistant in Physiology, with special qualifications in Experimental Physiology. Salary, $1200. Ten copies, typewritten or printed, of letter of application and testimonials should be in the hands Professorship in Chemistry by May 31st in the case of the undersigned, in the case of the Assistant of the Lectureship in Zoology and the Assistantship in Physiology by July 7th and in the case of the Lectureship in Botany by July 15th. Two copies of any published papers should be furnished as well. The successful candidates will be expected to enter upon their new duties about September 1st, 1919. The Secretary, Board of Governors WINNIPEG Botanical material and Microscopic Audubon's Birds of America Slides sent on application. State which is desired. For price lists and alli nformation regarding material, address GEO. M. GRAY, Curator, Woods Hole, Mass. The annual announcement will be sent on application to The Director, Marine Biological Laboratory, Woods Hole, Mass. 7 Volumes Octavo Edition |