SPENCER MON-OBJECTIVE 

 BINOCULAR MICROSCOPES 



Possess all the features of construction which 

 experience has shown to be meritorious and advan- 

 tageous. Among them is one very distinctive 

 feature which distinguishes the Spencer, viz.: 



Convergent eyepiece tubes 



which avoid the excessive and false conception of 

 perspective otherwise produced, giving a correct 

 interpretation of the object under examination. 

 Several models. 



Catalog sent on request 



Spencer Lens Company 



MANUFACTURERS OF 



No. 2H Mon-objective 

 Binoculas— $270.00 



Microscopes, Microtomes, Projection Lanterns, Photo- 

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BUFFALO, N. Y. 



WORTHY OF A PLACE 

 AMONG YOUR LITERATURE 



48 pages of interesting data on 

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^fje Mill Corporation 



Laboratory Apparatus - Chemicals - Glassware 

 ROCHESTER, N. Y. 



PSYCHOBIOLOGY 



A bi-monthly journal devoted to the field common 

 to Psychology and the Biological Sciences 



Edited by 



KNIGHT DUNLAP 



Johns Hopkins University 



PSYCHOBIOLOGY has been established to facilitate 

 the speedy publication of important research in 

 the field of psychobiological inquiry, and also to 

 emphasize the unity and importance of this field by 

 bringing together in one journal material which would 

 otherwise be scattered through the volumes of journals 

 of several different sciences. 



Five dollars a volume — United States and Canada. 

 Five dollars and fifty cents elsewhere. 



Order from WILLIAMS & WILKINS CO. 

 Baltimore, U. S. A. 



