SCIENCE— ADVERTISEMENTS 



JUST OUT 



The 

 Marine Decapod Crustacea 



of California 



By WALDO L. SCHMITT 



470 pages, 50 plates, 165 figures in text. 

 Paper, $5.00. Carriage extra, weight 3 J^ lbs. 



More than 200 valid species, including 

 eleven new ones, are systematically described 

 in this exhaustive treatise on these interesting 

 and, in many cases, economically important 

 forms. Forty-seven occur in San Francisco 

 Bay and receive special treatment. The 

 volume also includes a detailed discussion of 

 the geographical distribution of the decapods 

 and the influence upon them of salinity, tem- 

 perature and depth. 



The University of California Press 



Berkeley, California 19 East 47th Street, New York 



ROUGIER 



PHILOSOPHY AND 

 THE NEW PHYSICS 



The recent remarkable developments of 

 physical theories, especially those concerned 

 with relativity and quanta of energy, cannot 

 fail to have far-reaching influences on philo- 

 sophical thought. Prof. Rougier's very wide 

 reading in mathematical and experimental 

 physics enables him to present and interpret 

 the new advances in a very interesting way. 

 The book marks a measurable advance toward 

 a confluence of the broad streams of philo- 

 sophical and scientific enquiry. 



CLOTH $1.75 



By Louis Rougier, Prof. Agrege de Philo- 

 sophic (Paris). Authorized Translation 

 by Morton Masius, M.A., Ph.D., Worces- 

 ter Polytechnic Institute. 



P. BLAKISTON'S SON & CO., 

 Publishers : : : Philadelphia 



New 

 Spencer 

 Sliding 



No. 850 



for 

 Ceiloidin 



and 

 Paraffin 



Many new and unique features incorporated with Precision and Utility the paramount ideal. 



It's what the laboratory workers have long looked for. 



Send for bulletin T No. 4. Ready for shipment. 



SPENCER LENS COMPANY 



Manufacturers 



MICROSCOPES. MICROTOMES, DELINEASCOPES, ETC. 



BUFFALO, N. Y. 



