ADVERTISEMENTS. ix 
Guido Ferrari 
Drawing 
Optical and 
=a ~ Mathematical 
Te Instruments 
Experimental Work 
Models for Patent Office, Etc. 
DRAWING INSTRUMENTS A SPECIALTY. 
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Send for Price List—Mention American Naturalist. 
OF INTEREST TO ALL STUDENTS AND LOVERS OF NATURE. 
IGE OBSERVER 
All Departments of Nature Studies. 
OUR MOTTO: 
**Keep Your Eyes Open” 
(To observe the wonders and beauties of Nature. ) 
@ Official Organ of the Agassiz Association. 
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& 1.= The Outdoor World. 2. Agassiz Association. 
3. Practical Microscopy. 
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