The American Naturalist 



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THE SCIENCE PRESS 

 Lancaster, Pa. Garrison, N. Y. 



NEW YORK: Sub-Station 84 



THE BULLETIN —For bargains in Ethnolograph- 

 ical and Pre-historic Specimens. Books on Natural 

 History, Science, Travel, Voyages, etc. See The 



TENTH EDITION. 



THE MICROSCOPE, 



an introduction to Microscopic Methods and to Histology, 

 by SimohHbwky Gage, of Cornell University. Over 

 350 large octavo pages and above 250 figures in this new 

 and fully revisetfedition. Price $2.00, postpaid. 

 COMSTOCK PUBLISHING CO., Ithaca, N. Y. 



BIRDS' EGGS 



W. F. H. ROSENBERG, 

 57 Haverstock Hill, London, N. W., 

 England 



begs to announce the publication of a new 

 Price List (No. 15) of Birds' Eggs, con- 

 taining over 900 species from all parts of 

 the world. This Catalogue is systematic- 

 ally arranged, with author*' names, indica- 

 tions of localities, and an index to families, 

 it will be sent post free on application, as 



University of Colorado 



Mountain Laboratory 



Fourth summer session June 24 to Au- 

 gust 2, 1912. Courses in Field Biology 

 (animal and plant). Ecology, Systematic 

 Botany, Biology of Ponds and Streams. 

 Suitable work for undergraduates and grad- 

 uates. Daily Field excursions. 



The laboratory is at Tolland, Colo., in 

 the Bocky Mountains at an altitude of 

 8,889 feet. Climate cool and healthful. 

 Fees and expenses moderate. 



For pamphlet address the professor in 



Dr. Francis Ramaley 



University of Colorado 



Colorado 



