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OSCAR W. RICHARDS 



2. Stereoscopic and Inverted Microscopes 



The stereoscopic, biobjective microscope described in Section D2 

 is especially well adapted for manipulation of materials for examina- 

 tion at magnifications up to about 50 X. Although these instru- 

 ments are customarily furnished with the usual stand and a large 

 glass stage, they may also be used either directly on the table by re- 

 moving the base, or mounted on a long arm attached to a pedestal, or 

 mounted on a base board. 



For the study and microdissection of tissue cultures and for large, 

 heavy specimens an inverted microscope may be more convenient 

 (Fig. 11). The specimen is placed on the stage and its underside ex- 



Fig. 11. Diagram of an inverted microscope. 



amined by the objective, with a prism at the base to reflect the light 

 from the specimen up through the ocular to the observer. For trans- 

 parent specimens a mirror and condenser are mounted above the 

 specimen to reflect light through it to the objective. Special metallo- 

 graphic microscopes are available for the examination of metal sur- 

 faces and include a light source with vertical illuminator, inverted 

 microscope, and camera. 



