SCIENCE— ADVERTISEMENTS 



CORNELL UNIVERSITY 

 MEDICAL COLLEGE 



First Avenue and Twenty-eighth Street 

 NEW YORK CITY 



The first year of the course is also 

 offered at Ithaca, N. Y., subsequent 

 years at New York City only. 



For Information Address 

 THE SECRETARY 



The Microscope 



By SIMON H. GAGE of Cornell University 



13th Edition, Published December, 1920 



In this edition, special emphasis is fut upon the Dark-Field 

 Microscope. POSTPAID $3.00. 



COMSTOCK PUBLISHING CO., Ithaca, N. Y. 



Marine Biological Laboratory 



WOODS HOLE, MASS. 



Biological Material 



,<<-^Y;i-w,, .1- ZOOLOGY. Preserved mate- 

 /? * rial of all types of animals for class 



f work and for the museum. 



! ; 2. EMBRYOLOGY. Stages of 



V some invertebrates, fishes (includ- 



ing Acanthias, Amia and Lepidos- 

 tus), Amphibia, reptiles aad some 



I mammals. 



.3. BOTANY. Preserved mate- 

 rial of Algae, Fungi, LiverwortSi 

 Mosses, Ferns and Seed Plants. 



4. MICROSCOPE SLIDES in Bacteriology, 

 Botany and Zoology. 



5. LIFE HISTORIES, Germination Studies, 

 and Natural History Groups. 



Catalogues furnished on application to 



GEORGE M. GRAY, Curator 



WOODS HOLE, MASSACHUSETTS 



CARNEGIE INSTITUTION OF WASHINGTON 

 Publications More Recently Issued: 



313. Hall, H. M., and F. L. Long. Rubber-content of 

 North American Plants. Octavo, 65 pp., 3 pls.__$1.00 



314. Loftfield, J V. G. The Behavior of Stomata. Oc- 

 tavo, 104 pp., 1(3 pis., 54 figures.- __ __$1.50 



f 



315 Clements, F. E. Aeration and Air-conent: The Role 



of Oxygen in Root Activity. Octavo, 183 pp., 52.00 



316. Weaver, J. E., F. C. Jean, and J. W. Crist. De- 

 velopment and Activities of Roots of Crop Plants. 

 Octavo, 122 pp., 14 plates, 42 figures $2.00 



317. Hayford, John F. Effects of Winds and of Baro- 

 metric Pressures upon the Great Lakes. Octavo, 

 139 pp., 16 plates i $2.75 



315. Wyckoff, Ralph W. G. The Analytical Expression 

 the Results of the Theory of Space-Groups. Octavo, 

 ISO pp., 34 figures §3.25 



319. Cooper, W. S. The Broad-Sclerophyll Vegetation of 

 California: An Ecological Study of the Chaparral 

 and its Related Communities. Octavo, 124 pp . 31 

 plates, ZZ figures $2.00 



320. Castle, W. E. Genetic Studies of Rabbits and Rats. 

 Octavo, 55 pp., 2 plates, 7 figures $1.00 



321. Case, E. C. New Reptiles and Stegocephalians from 

 the Upper Triassic of Western Texas. Quarto, 84 

 pp., 14 plates, 33 figures $2 00 



Orders for above publications may be ma.de through book- 

 sellers or sent directly to the Institution. 

 All communications should be addressed to: 



CARNEGIE INSTITUTION OF WASHINGTON 



WASHINGTON, D. C. 



Publications of 

 The Philippine Bureau of Science 



AIWPHIEIANS AND TURTLES OF THE PHIUPPINE 

 ISLANDS. By E. H. Taylor. 193 pages, 17 plates, and 

 9 text figures; postpaid $1.00. 



THE SNAKES OF THE PHILIPPINE ISLANDS. By 



E. H. Taylor. 316 pages, 37 plates, and 32 te.xt figures; 

 postpaid $2.50. 



THE LIZARDS OF THE PHILIPPINE ISLANDS. By 



E. H. Taylor. 272 pages, 23 plates, and 53 text figures; 

 postpaid $2.50. In press. 



VEGETATION OF PHILIPPINE MOUNTAINS. By W. 



H. Brown. 434 pages, 41 plates, and 30 te.xt figures; 

 postpaid $2.50. 



INDEX TO THE GENERA OF BIRDS. By R. C. Mc- 

 Gregor. 185 pages postpaid $1.00. 



SPECIES BLANCOANAE. By E. D. Merrill. 424 pages; 



postpaid $2.25. 



AN INTERPRETATION OF RUMPHIUS'S HERBA- 

 RIUM AMBOINENSE. By E. D. Merrill. 595 pages, ■ 

 2 maps; postpaid $3.00. 



THE PHILIPPINE JOURNAL OF SCIENCE, a monthly 

 (no longer issued in sections), per year $5.00. 



_A list of the publications of the Philippine Bureau of 

 Science and a sample copy of the Philippine Journal of 

 Science will be sent upon request. 



Subscriptions and orders for publications should be sent to 



THE BUSINESS MANAGER 

 Philippine Journal of Science 



Bureau of Science, Manila, P. I. 



